Page 1

Tranche 2 Junction Mitigation Options Report WHITEHILL BORDON ECO-TOWN EVIDENCE BASE 00900001/005 (September 2011)


Jo b No .: CO00900001

TA Ke y F in d ings Re port Wh itehill Bo rdon Eco -town Ev iden ce Base Re p ort No .: 00900001/005 Revision No.: Draft Final Date of issue: September 2011

Amey Caburn House

Hampshire County Council

Brooks Road

The Castle

Lewes

Winchester

East Sussex

Hampshire

B N7 2 B Y

SO23 8UD

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Chapters and Appendices 1

Introduction .....................................................................................................1

1.1

Background.....................................................................................................1

1.2

Objective.........................................................................................................1

2

Junction Mitigation Investigation Methodology...............................................2

3

A31/B3001 Hickleys Corner .............................................................................5

3.1

Junction Information.........................................................................................5

3.2

Design Rationale .............................................................................................6

3.3

Revised Junction Operation..............................................................................9

3.4

Junction Improvement Cost Estimate ..............................................................10

4

A31/A325 Coxbridge Roundabout..................................................................11

4.1

Junction Information.......................................................................................11

4.2

Design Rationale ...........................................................................................12

4.3

Revised Junction Operation............................................................................13

4.4

Junction Improvement Cost Estimate ..............................................................14

5

A325/School Hill Mini-roundabout .................................................................16

5.2

Design Rationale ...........................................................................................17

5.3

Revised Junction Operation............................................................................19

5.4

Junction Improvement Cost Estimate ..............................................................20

6

A325/B3004 Junction.....................................................................................21

6.1

Junction Information.......................................................................................21

6.2

Design Rationale ...........................................................................................22

6.3

Revised Junction Operation............................................................................23

6.4

Junction Improvement Cost Estimate ..............................................................24

7

B3004/Paper Mill Lane Junction.....................................................................26

7.1

Junction Information.......................................................................................26

7.2

Design Rationale ...........................................................................................27

7.3

Revised Junction Operation............................................................................27

7.4

Junction Improvement Cost Estimate ..............................................................28

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8

A325/Tesco Access/Woolmer Way Junction..................................................29

8.1

Junction Information.......................................................................................29

8.2

Design Rationale ...........................................................................................29

8.3

Revised Junction Operation............................................................................30

8.4

Junction Improvement Cost Estimate ..............................................................31

9

A325/Liphook Rd/Firgrove Rd Roundabout ...................................................32

9.1

Junction Information.......................................................................................32

9.2

Design Rationale ...........................................................................................33

9.3

Revised Junction Operation............................................................................34

9.4

Junction Improvement Cost Estimate ..............................................................35

10

A325/Petersfield Road Roundabout...............................................................36

10.1

Junction Information.......................................................................................36

10.2

Design rationale.............................................................................................36

10.3

Revised Junction Operation............................................................................37

10.4

Junction Improvement Cost Estimate ..............................................................38

11

A325/A3 (Eastbound) Slip-roads....................................................................39

11.1

Junction Information.......................................................................................39

11.2

Design Rationale ...........................................................................................39

11.3

Revised Junction Operation............................................................................40

11.4

Junction Improvement Cost Estimate ..............................................................40

11.5

Slip-road Geometry and Collision Analysis......................................................41

12

A3/B3006 Roundabout...................................................................................43

12.1

Junction Information.......................................................................................43

12.2

Design Rationale ...........................................................................................44

12.3

Revised Junction Operation............................................................................47

12.4

Junction Improvement Cost Estimate ..............................................................48

12.5

Collision Analysis...........................................................................................48

13 13.1

B3004/Oakhanger Road Junction ..................................................................50 Junction Information.......................................................................................50

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13.2

Design Rationale ...........................................................................................50

13.3

Revised Junction Operation............................................................................51

13.4

Junction Improvement Cost Estimate ..............................................................53

14

A325/B3002 Station Road Junction................................................................54

14.1

Junction Information.......................................................................................54

14.2

Design Rationale ...........................................................................................54

14.3

Revised Junction Operation............................................................................56

14.4

Junction Improvement Cost Estimate ..............................................................57

15

B3006/Petersfield Road Junction...................................................................58

15.1

Junction Information.......................................................................................58

15.2

Design Rationale ...........................................................................................58

15.3

Revised Junction Operation............................................................................59

15.4

Junction Improvement Cost Estimate ..............................................................59

16

Summary & Conclusions ...............................................................................60

Appendix A:

A31/HickleysCorner Junction

Appendix B:

A31/A325 Coxbridge Roundabout

Appendix C:

A325/School Hill Mini-Roundabout

Appendix D:

A325/B3004 Junction

Appendix E:

B3004/Paper Mill Lane Junction

Appendix F:

A325/Tesco Access/Woolmer Way Junction

Appendix G:

A325/LiphookRoad/Firgrove Road Roundabout

Appendix H:

A325/Petersfield Road Roundabout

Appendix I:

A325/A3 (Eastbound) Slip-roads

Appendix J:

A3/B3006 Roundabout

Appendix K:

B3004/Oakhanger Road Junction

Appendix L:

A325/B3002 Station Road Junction

Appendix M:

B3006/Petersfield Road Junction

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1

Introduction

1.1

Background

1.1.1

Amey Consulting were commissioned by Hampshire County Council (HCC) (on behalf of East Hampshire District Council) in July 2010 to undertake a Transport Assessment (TA), which together with a Transport Model produced by MVA Consultancy, formspart of a robust and credible evidence base to support proposalsfor the potential re-development and expansion of Whitehill Bordon asan Eco-town.

1.1.2

The TA, which comprisesTranche 1 of the transportation body of work forming the Whitehill Bordon Eco-town Evidence Base, investigated the traffic impactsof a number of proposed development scenarioson the surrounding highway networkand, in particular, on 20 key junctions; identified in conjunction with highway officersfrom HCC, Surrey County Council (SCC), East Hampshire District Council (EHDC) and the Highways Agency (HA).

1.1.3

The outcomesof the Tranche 1 TA identified those key junctionson the surrounding road network that would operate over capacity in the forecast year 2026 both with and without development at Whitehill Bordon, and if the proposed Eco-town development were implemented and certain car mode share and trip containment levelsachieved. The TA then recommended an investigation into the appropriate mitigation of these junctions, in order to demonstrate that there were no ‘showstoppers’ to development as a result of the traffic impact of the Eco-town.

1.1.4

Thisreport should be read in conjunction with the Tranche 1 Transport Assessment and/or the TA Key Findings Report, both produced by Amey on behalf of HCC and EHDC.

1.2

Obj ective

1.2.1

Thisreport, which formsTranche 2 of the transportation body of workfor the purposes of the Whitehill Bordon Eco-town Evidence Base, follows on from the findings of the TA and investigatesoptionsto mitigate the traffic impact of the development proposals. The objective of this tranche of work, as detailed within the workpackage brief, is: “To study in further detail the network locations which are shown through the Transport Assessment to operate at or above design capacity in the future year peak periods, to develop engineering options for improvement, and to ensure that the traffic impact of the development can be accommodated satisfactorily on the network for the purposes of the LDF Core Strategy.”

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2

Junction Mitigation Investigation Methodology

2.1.1

The proposed mitigation of the surrounding highway networkhasbeen based upon two alternative proposed development scenario iterationsin the forecast year 2026. The alternative scenariosrelate to the level of car mode share and the level of trip containment achieved by the development, asdiscussed in greater detail within the TA. Both scenarios comprise the same quantum of development (4,000 dwellings) and the implementation of traffic management measureson the existing A325 in the town centre to divert traffic onto a proposed inner relief road, in accordance with the findingsof the Transport Assessment. The two alternative development scenariosto be mitigated against are set out below: •

2026 Development Scenario 1 – 50% car mode share/50% trip containment/A325 Traffic Management (asrecommended within the TA)

2026 Development Scenario 2 – 75% car mode share/30% trip containment/A325 Traffic Management (’worst case’)

2.1.2

The ‘Traffic Impact Assessments’ Chapter of the TA established that, of the 20 identified key junctionson the surrounding highway network, 10 junctions would operate over capacity during peakhighway periodsin 2026 if any of the proposed development scenarioswere implemented.

2.1.3

The 10 over capacity junctionsand their relevant highway authority are set out below: •

A31/B3001 HickleysCorner (SCC)

A31/A325 Coxbridge Roundabout (SCC)

A325/School Hill Mini-roundabout (SCC)

A325/B3004 Junction (HCC)

B3004/Paper Mill Lane Junction (HCC)

A325/Tesco Access/Woolmer Way Junction (HCC)

A325/LiphookRoad/Firgrove Road Roundabout (HCC)

A325/Petersfield Road Roundabout (HCC)

A325/A3 (Eastbound) Slips(HA)

A3/B3006 Roundabout (HA)

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2.1.4

Further to discussions with HCC, SCC and the HA, it was determined that thisstudy would only attempt to mitigate those junctionsunder SCC and HA authority against the ‘worst case’ traffic impactsof the development. The junctionsunder HCC authority have been mitigated fully against future year background traffic growth, nearby committed developmentsand Whitehill Bordon development generated traffic.

2.1.5

The HA also requested that the proposed mitigation design processat the junctionsunder their authority considered safety records at the junction. As such the latest 5 year personal injury collision data wasrequested for the A325/A3 (Eastbound) Slipsand A3/B3006 Roundabout junctionsand analysed as appropriate.

2.1.6

With regard to the B3004/Paper Mill Lane junction, a proposed mitigation design comprising a double mini-roundabout was provided by HCC, following recent consideration of the potential for improvement of the junction in association with a proposal for local development. Thisstudy, therefore, hasassessed the operational capacity of the proposal when the Eco-town impact isconsidered only, and not considered further mitigation proposals.

2.1.7

In addition to the junctionsabove, a further 3 junctionswere shown, within the TA, to operate within capacity in development Scenario 1 but would operate at or over capacity within the development Scenario 2. The mitigation of the 3 junctionsbelow has, therefore, also been considered against the ‘worst case’ traffic impactsof the development:

2.1.8

B3004/Oakhanger Road Junction (HCC)

A325/B3002 Station Road (HCC)

B3006/Petersfield Road Junction (HCC)

As agreed with the project team the mitigation investigation of each junction location consists of the following: •

Setting out of the proportionate impact of the development proposals(asappropriate);

Engineered mitigation optionsdrawings;

Associated text outlining the design rationale and highlighting constraints;

Revised junction capacity assessments;

Feasibility Level cost estimatesfor each mitigation option

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2.1.9

It should be noted that the cost estimateshave been developed asaccurately as possible based upon the preliminary design stage drawings. A nominal sum for the diversion of statutory undertaker’s plant hasbeen incorporated; however, these are likely to change upon full investigation of plant at detailed design stage. Furthermore, the costsrepresent an approximate construction cost only for each mitigation option. The costsdo not incorporate consultant’sfees, contingenciesand have not considered optimism biasat thisstage.

2.1.10

In order to aid the mitigation design processpublic highway boundary information was obtained from HCC and SCC.

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3

A31/B3001 Hickleys Corner

3.1

Junction Information

3.1.1

The A31/B3001 HickleysCorner junction isa signalised crossroads situated to the North North East of Bordon within the bordersof Surrey.

3.1.2

The capacity of the junction hasbeen assessed during weekday AM and PM peakhoursfor the 2026 baseline and 2026 proposed development scenarios, as set out within the Whitehill Bordon Eco-town Evidence Base Transport Assessment. The assessments indicate that the junction would operate over capacity during both the AM and PM peakperiodswithin the 2026 baseline (without any development at Whitehill Bordon) and within the ‘worst case’ proposed development scenario in 2026. Table 3.1 and Table 3.2, below, provide a summary of the AM and PM peakforecast year capacity assessments of the junction in its current form, respectively:

Table 3.1: A31/B3001 Hickleys Corner – 2026 AM Peak Capacity Assessment Summary 2026 Baseline Link Flow (Total)

Max DoS

2026 Dev elopment Scenario 2 (75%/30%)

Mean Max Q (v eh)

Flow (Total)

Max DoS

Mean Max Q (v eh)

A31 (N)

2045

116.5%

75.4

2225

120.6%

96.1

B3001 Station Hill

693

115.0%

46.5

693

127.1%

65.2

A31 (S)

1530

116.0%

74.4

1788

125.8%

115.8

B3001 South Street

505

118.4%

40.4

514

128.3%

53.4

Table 3.2: A31/ A31/B3001 Hickleys Corner – 2026 PM Peak Capacity Assessment Summary 2026 Baseline Link Flow (Total)

Max DoS

2026 Dev elopment Scenario 2 (75%/30%)

Mean Max Q (v eh)

Flow (Total)

Max DoS

Mean Max Q (v eh)

A31 (N)

2236

131.3% 128.1

2347

140.1%

158.9

B3001 Station Hill

573

117.8%

44.1

592

121.6%

50.8

A31 (S)

1353

100.7%

30.3

1377

102.5%

34.6

B3001 South Street

676

131.4%

75.4

702

136.6%

86.3

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3.1.3

The above tablesindicate that all armsof the junction would operate significantly over capacity during both the AM and PM peakhighway periodswithin any of the 2026 forecast year scenarios with significant queuing on all arms.

3.1.4

In order to resolve the existing and future congestion issuesat the junction a junction appraisal wasundertaken in 2004 on behalf of SCC. The appraisal identified a long term solution for the junction with the main aimsof reducing congestion on the strategic and local road network, improving road safety and conditionsfor pedestriansand cyclists; and resolving the issue of severance currently caused by the A31 at thisjunction.

3.1.5

The scheme proposed the implementation of an on-line A31 underpass. The existing surface level signal junction would be converted to a roundabout with the grade-separated A31 passing beneath it. Single lane slip roadswould provide access between the roundabout and the A31 with signalised crossing facilitiesprovided for pedestriansand cyclists.

3.1.6

A bid for major scheme funding for the proposalswassubmitted and rejected by the Department for Transport in 2008. Thisstudy, therefore, aimsto develop an interim proposal to mitigate against the traffic impact of the Whitehill Bordon Eco-town.

3.2

Design Rationale

3.2.1

The potential mitigation feasibility design options are shown within drawings 00900001/GA/004 - 00900001/GA/005, contained within Appendix A of thisreport.

3.2.2

The proposed measuresat thisjunction are intended to mitigate against the ‘worst case’ traffic impactsof the proposed development only, and do not intend to resolve all existing operational issuesat the junction. The proportional increase in forecast year traffic flow through the junction of the proposed ’worst case’ development scenario compared with the 2026 baseline isshown in Table 3.3 below:

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Table 3.3: A31/ A31/B3001 Hickleys Corner – Traffic Impact of Dev elopment Proposals

Peak Period

AM

PM

3.2.3

Arm

2026 Baseline

2026 Development Scenario 2 (75%/30%)

Flow

Flow

%Dif

A31 (N)

2045

2225

+9%

B3001 Station Hill

693

693

0%

A31 (S)

1530

1788

+17%

B3001 South Street

505

514

+2%

Total

4773

5220

+9%

A31 (N)

2236

2347

+5%

B3001 Station Hill

573

592

+3%

A31 (S)

1353

1377

+2%

B3001 South Street

676

702

+4%

Total

4838

5018

+4%

The capacity assessments and traffic impact summary above indicate that predominantly the A31 (N) and A31 (S) arms of the junction require physical improvement works in order to mitigate against the ’worst case’ impacts of the development proposals.

3.2.4

Drawing 00900001/GA/004 showsthe initial mitigation design (Option 1) for the junction. The proposed measurescomprise the conversion of the nearside lane of the A31 (N) and A31 (S) approachesfrom ‘left only’ to ‘left and ahead’ and the provision of an additional exit lane on both armsto accommodate the straight ahead movement. The additional nearside exit lane then mergesinto the existing A31 dual carriageway approximately 40 metres downstream of the junction in either direction with a merge taper length of approximately 120 metres. The proposed measureswould require the removal of the existing splitter island between the nearside and centre laneson the A31 (N) arm of the junction.

3.2.5

As the mitigation proposalsincorporate changesto the operation of the nearside laneson both A31 armsand the removal of the splitter island on the A31 (N) arm, the method of control (MOC) of the junction hasbeen revised to accommodate the revised movements allowed within the junction. The revised MOC, shown in Figure 3.4 below, involvesthe removal of the left only phase on the A31 (N) arm and the removal of the stage incorporating thisphase.

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Table 3.4: Rev ised A31/B3001 Hickleys Corner – Method of Control Min: 7 2

Min: 7 3

B

1

Min: 7 E

M

M

C

L K

N

K

J

H

H

J

I

D

A

G

G

F

12

3.2.6

29s

9

17s

12

11s

The intergreensincorporated within the junction’sMOC have been amended as a result of the stop lineson the B3001 Station Hill and B3001 South Street armsbeing moved backto accommodate the additional exit lane on both A31 armsof the junction. Existing phase delaysincorporated within the junction control have also been removed.

3.2.7

Capacity assessments were undertaken based upon the proposed measures set out within drawing 00900001/GA/004 to evaluate the impact of the proposed improvementson the operation of the junction. The assessment results indicated that the Option 1 design would continue to operate worse than 2026 baseline conditionson the A31 (N) and B3001 Station Hill armsin both the AM and PM peakperiods; and on the B3001 South Street arm in the PM peak. The full Option 1 capacity assessment outputsare contained within Appendix A of thisreport.

3.2.8

As the proposed measureswithin Option 1 were not sufficient to appropriately mitigate the junction against the traffic impact of the ’worst case’ development scenario 2, a further mitigation option wasconsidered at the junction. A previousstudy undertaken at the junction on behalf of Surrey County Council (SCC) in 2004, highlighted a historic issue regarding pedestrian safety at the junction which to date has not been resolved. The issue of pedestrian safety hasbeen considered in further detail within mitigation Option 2.

3.2.9

Drawing 00900001/GA/005 showsthe revised mitigation design (Option 2) for the junction. The revised mitigation measuresare based upon the lane provision and MOC detailed within Option 1 but also comprise the removal of the existing pedestrian crossing facilitieson the A31 arms of the junction and the provision of a pedestrian overbridge crossing facility located to the north of the junction. The removal of at-grade pedestrian crossingson the A31 would improve the operation of the junction asassociated intergreens would also be removed from the MOC. The provision of a pedestrian overbridge crossing facility would also improve pedestrian safety at the junction by reducing the interaction between vehicular traffic and pedestrians. The existing at-grade pedestrian crossings on the B3001 Station Hill arm of the junction would be retained.

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3.2.10

The Option 2 mitigation proposalswould also require an appropriate pedestrian crossing facility to be provided somewhere along the B3001 South Street arm away from the junction in order to facilitate all east-west pedestrian desire lines. It should also be noted that the provision of a pedestrian overbridge facility may have associated environmental issues associated with its implementation that have not been fully considered at this feasibility stage.

3.3 3.3.1

Rev ised Junction Operation The revised Option 2 junction arrangement hasbeen assessed for capacity during weekday AM and PM peakhoursfor the proposed ‘worst case’ 2026 development scenario 2.Table 3.5 and Table 3.6 below provide a summary of the AM and PM peakforecast year capacity assessments of the junction in itsrevised form to allow a comparison against the operation of the existing arrangement. The full modelling inputsand capacity assessment outputsare contained within thisreport within Appendix A.

Table 3.5: Rev ised A31/B3001 Hickleys Corner – 2026 AM Peak Capacity Assessment Summary 2026 Baseline Link Flow (Total)

Max DoS

2026 Dev elopment Scenario 2 (75%/30%)

Mean Max Q (v eh)

Flow (Total)

Max DoS

Mean Max Q (v eh)

A31 (N)

2045

116.5%

75.4

2225

107.5%

51.6

B3001 Station Hill

693

115.0%

46.5

693

110.5%

38.9

A31 (S)

1530

116.0%

74.4

1788

77.9%

14.6

B3001 South Street

505

118.4%

40.4

514

108.0%

27.5

Table 3.6: Rev ised A31/B3001 Hickleys Corner – 2026 PM Peak Capacity Assessment Summary 2026 Baseline Link Flow (Total)

Max DoS

2026 Dev elopment Scenario 2 (75%/30%)

Mean Max Q (v eh)

Flow (Total)

Max DoS

Mean Max Q (v eh)

A31 (N)

2236

131.3% 128.1

2347

119.3%

89.0

B3001 Station Hill

573

117.8%

44.1

592

114.5%

40.7

A31 (S)

1353

100.7%

30.3

1377

63.5%

10.2

B3001 South Street

676

131.4%

75.4

702

116.6%

53.3

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3.3.2

The capacity assessments summarised above indicate that the proposed measureswithin Option 2 would appropriately mitigate all armsof the roundabout against the ‘worst case’ traffic impact of the development proposals. With the proposed Transport Strategy designed to minimise external car trips from Whitehill Bordon, it isexpected that the actual junction performance will be further improved by achieving higher containment and lower car modeshare than asset out in the ‘worst case’ assessment.

3.4

Junction Improv ement Cost Estimate

3.4.1

An indicative cost estimate hasbeen developed for the proposed Option 2 improvement works at the junction to mitigate the traffic impactsof the proposed development. A summary of the feasibility stage cost estimate for the proposed improvementsiscontained within this report as Appendix A.

3.4.2

It is estimated that the proposed highway worksat the A31/B3001 HickleysCorner would cost approximately £322,000. It should be noted, however, that the cost estimate isonly indicative at this stage as they are based upon preliminary junction design. The cost estimate of the highway works may be subject to change at detailed design stage.

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4

A31/A325 Coxbridge Roundabout

4.1

Junction Information

4.1.1

The A31/A325 Coxbridge Roundabout junction isa standard roundabout situated to the North of Bordon, within Surrey.

4.1.2

The capacity of the roundabout hasbeen assessed during weekday AM and PM peakhours for the 2026 baseline and 2026 proposed development scenarios, as set out within the Whitehill Bordon Eco-town Evidence Base Transport Assessment. The assessments indicate that the junction would operate over capacity during both the AM and PM peakperiodswithin the 2026 baseline without development at Whitehill Bordon, and within the ‘worst case’ proposed development scenario in 2026. Table 4.1 and Table 4.2, below, provide a summary of the AM and PM peakforecast year capacity assessments of the junction in its current form, respectively:

Table 4.1: A31/A325 Coxbridge Roundabout – 2026 AM Peak Capacity Assessment Summary 2026 Baseline Link

2026 Dev elopment Scenario 2 (75%/30%)

Flow (Total)

Max RFC

Max Queue (v eh)

Flow (Total)

Max RFC

Max Queue (v eh)

A325 (N)

366

0.598

1.5

384

0.670

2.0

A31 (E)

1535

0.907

8.8

1697

1.018

39.7

A325 (S)

1211

1.491

249.8

1251

1.511

269.2

A31 (W)

1326

0.775

3.4

1496

0.884

7.1

Table 4.2: A31/A325 Coxbridge Roundabout – 2026 PM Peak Capacity Assessment Summary 2026 Baseline Link

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2026 Dev elopment Scenario 2 (75%/30%)

Flow (Total)

Max RFC

Max Queue (v eh)

Flow (Total)

Max RFC

Max Queue (v eh)

A325 (N)

718

1.172

64.4

880

1.439

163.5

A31 (E)

1909

1.227

210.6

2022

1.308

305.1

A325 (S)

960

1.145

74.2

1014

1.178

97.1

A31 (W)

1160

0.642

1.8

1162

0.656

1.9

11


4.1.3

The above tablesindicate that the A325 (S) arm of the junction would operate significantly over capacity during both the AM and PM peakhighway periodswithin any of the 2026 forecast year scenarios. The A325 (N) and A31 (E) arms would also operate significantly over capacity during the PM peakperiod within any of the 2026 forecast year scenarios.

4.2

Design Rationale

4.2.1

The proposed mitigation feasibility design optionsare shown within drawings 00900001/GA/006 - 00900001/GA/007, contained within Appendix B of thisreport.

4.2.2

The proposed measuresat thisjunction are intended to mitigate against the ‘worst case’ traffic impactsof the proposed development only, and not to resolve all existing issuesat the junction. The proportional increase in forecast year traffic flow through the junction of the proposed ‘worst case’ development scenario compared with the 2026 baseline isshown in Table 4.3 below:

Table 4.3: A31/A325 Coxbridge Roundabout – Traffic Impact of Dev elopment Proposals

Peak Period

AM

PM

4.2.3

Arm

2026 Baseline

2026 Development Scenario 2 (75%/30%)

Flow

Flow

%Dif

A325 (N)

366

384

+5%

A31 (E)

1535

1697

+11%

A325 (S)

1211

1251

+3%

A31 (W)

1326

1496

+13%

Total

4438

4828

+9%

A325 (N)

718

880

+23%

A31 (E)

1909

2022

+6%

A325 (S)

960

1014

+6%

A31 (W)

1160

1162

0%

Total

4747

5078

+7%

The capacity assessments, summarised above, indicate that the A325 (N), A31 (E) and A325 (S) arms of the junction would require physical mitigation worksto improve capacity. Furthermore, at present the A31 (E), A325 (S) and A31 (W) arms do not achieve the minimum standard deflection in order to slow vehicle speedson the approach to the roundabout.

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4.2.4

Drawing 00900001/GA/006 showsthe initial mitigation design (Option 1) for the roundabout. Kerbline realignment hasenabled the entry widths, together with effective flare length (one of the most significant factorsaffecting capacity at a roundabout entry), to be increased at each of the over capacity approachesto the roundabout. At the A325 (N) arm the entry width has been increased from 6.5 metres to 8.0 metres, from 7.8 metresto 9.0 metresat the A31 (E) arm; and from 6.8 metresto 7.5 metresat the A325 (S) arm.

4.2.5

Capacity assessments were undertaken based upon the proposed measures set out within drawing 00900001/GA/006 to evaluate the impact of the proposed improvementson the operation of the junction. The assessment results indicated that the Option 1 design would continue to operate worse than 2026 baseline conditionson the A31 (E) arm in both the AM and PM peakperiodsand on the A31 (W) arm in the AM peak. The full Option 1 capacity assessment outputsare contained within Appendix B of thisreport.

4.2.6

As the proposed measureswithin Option 1 were not sufficient to appropriately mitigate the junction against the traffic impact of the ‘worst case’ development Scenario 2, a further mitigation option wasconsidered at the roundabout. Drawing 00900001/GA/007 showsthe revised mitigation design (Option 2) for the roundabout. The proposed mitigation measures within Option 2 comprise the incorporation of subsidiary deflection islands on the A31 (E) and A31 (W) arms of the roundabout.

4.2.7

The implementation of subsidiary deflection islandswould enable the entry widthsand effective flare lengthson the critical A31 armsof the junction to be further increased in addition to improving the deflection on the approach to the roundabout on these arms. At the A31 (E) arm of the junction the entry width hasbeen increased from 7.8 metresat present to 12.0 metresand the effective flare length increased from 0.0 to 12.0 metres. At the A31 (W) arm of the junction the entry width hasbeen increased from 10.10 metres at present to 13.0 metresand the effective flare length increased from 0.0 to 10.0 metres.

4.2.8

Additional kerb realignment on the A325 (N) and A325 (S) armsalso enable the entry widths on these arms to be increased further when compared with the Option 1 mitigation design. At the A325 (N) arm the entry width hasbeen increased from 6.5 metresat present to 9.0 metresand from 6.8 metresto 8.0 metresat the A325 (S) arm.

4.3

Rev ised Junction Operation

4.3.1

The revised Option 2 junction arrangement hasbeen assessed for capacity during weekday AM and PM peakhoursfor the 2026 baseline and 2026 proposed development scenarios. Table 4.4 and Table 4.5 below provide a summary of the AM and PM peakforecast year capacity assessments of the junction in itsrevised form to allow a comparison against the operation of the existing arrangement. The full capacity assessment outputsare contained within thisreport within Appendix B.

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Table 4.4: Rev ised A31/A325 Coxbridge Roundabout – 2026 AM Peak Capacity Assessment Summary 2026 Baseline Link

2026 Dev elopment Scenario 2 (75%/30%)

Flow (Total)

Max RFC

Max Queue (v eh)

Flow (Total)

Max RFC

Max Queue (v eh)

A325 (N)

366

0.598

1.5

384

0.527

1.1

A31 (E)

1535

0.907

8.8

1697

0.822

4.5

A325 (S)

1211

1.491

249.8

1251

1.347

192.1

A31 (W)

1326

0.775

3.4

1496

0.885

7.2

Table 4.5: Rev ised A31/A325 Coxbridge Roundabout – 2026 PM Peak Capacity Assessment Summary 2026 Baseline Link

4.3.2

2026 Dev elopment Scenario 2 (75%/30%)

Flow (Total)

Max RFC

Max Queue (v eh)

Flow (Total)

Max RFC

Max Queue (v eh)

A325 (N)

718

1.172

64.4

880

1.109

55.9

A31 (E)

1909

1.227

210.6

2022

1.106

116.3

A325 (S)

960

1.145

74.2

1014

1.156

83.1

A31 (W)

1160

0.642

1.8

1162

0.638

1.7

The capacity assessments summarised above indicate that the proposed measureswithin Option 2 would appropriately mitigate all armsof the roundabout against the ‘worst case’ traffic impact of the development proposals. The A325 (N), A31 (E) and A325 (S) armsin the AM peakand all armsof the junction in the PM peakwould operate with increased capacity in 2026 if the mitigation Option 2 proposalswere implemented when compared with the existing arrangement within the 2026 baseline scenario. With the proposed Transport Strategy designed to minimise external car trips from Whitehill Bordon, it isexpected that the actual junction performance will be further improved by achieving higher containment and lower car mode-share than as set out in the ‘worst case’ assessment.

4.4

Junction Improv ement Cost Estimate

4.4.1

An indicative cost estimate hasbeen developed for the proposed Option 2 improvement works at the junction to mitigate the traffic impactsof the proposed development. A summary of the feasibility stage cost estimate for the proposed improvements iscontained within this report as Appendix B.

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4.4.2

It is estimated that the proposed highway worksat the A31/A325 Coxbridge Roundabout would cost approximately ÂŁ174,000. It should be noted, however, that the cost estimate is only indicative at thisstage as they are based upon preliminary junction design. The cost estimate of the highway works may be subject to change at detailed design stage.

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5

A325/School Hill Mini-roundabout

5.1.1

The A325/School Hill junction isa mini-roundabout situated to the north of Bordon in the village of Wrecclesham, Surrey.

5.1.2

The capacity of the roundabout hasbeen assessed during weekday AM and PM peakhours for the 2026 baseline and 2026 proposed development Scenario 2, asset out within the Whitehill Bordon Eco-town Evidence Base Transport Assessment. The assessments indicate that the junction would operate over capacity during both the AM and PM peakperiodswithin the 2026 baseline and within the ‘worst case’ proposed development scenario in 2026. Table 5.1 and Table 5.2, below, provide a summary of the AM and PM peakforecast year capacity assessments of the junction in itscurrent form, respectively:

Table 5.1: A325/School Hill Mini-Roundabout – 2026 AM Peak Capacity Assessment Summary 2026 Baseline Link

2026 Dev elopment Scenario 2 (75%/30%)

Flow (Total)

Max RFC

Max Queue (v eh)

Flow (Total)

Max RFC

Max Queue (v eh)

A325 (N)

797

0.842

5.0

970

1.039

35.6

School Hill

479

0.651

1.8

479

0.736

2.7

A325 (S)

549

1.100

36.0

731

1.447

144.3

Table 5.2: A325/School Hill Mini-Roundabout – 2026 PM Peak Capacity Assessment Summary 2026 Baseline Link

5.1.3

2026 Dev elopment Scenario 2 (75%/30%)

Flow (Total)

Max RFC

Max Queue (v eh)

Flow (Total)

Max RFC

Max Queue (v eh)

A325 (N)

1190

1.230

140.1

1508

1.573

404.1

School Hill

233

0.378

0.6

233

0.398

0.7

A325 (S)

563

0.865

5.6

669

1.040

27.7

The above tablesindicate that the A325 (S) arm of the junction would operate significantly over capacity during the AM peak highway period within both of the 2026 forecast year scenarios. The A325 (N) arm would also operate significantly over capacity during the PM peakperiod within both of the 2026 forecast year scenarios.

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5.2

Design Rationale

5.2.1

The proposed mitigation feasibility design optionsare shown within drawings 00900001/GA/008 - 00900001/GA/010, contained within Appendix C of thisreport.

5.2.2

The proposed measuresat thisjunction are intended to mitigate against the ‘worst case’ traffic impactsof the proposed development only. The proportional increase in forecast year traffic flow through the junction of the proposed ‘worst case’ development scenario compared with the 2026 baseline isshown in Table 5.3 below:

Table 5.3: A325/School Hill Mini-Roundabout – Traffic Impact of Dev elopment Proposals

Peak Period

AM

PM

5.2.3

Arm

2026 Baseline

2026 Development Scenario 2 (75%/30%)

Flow

Flow

%Dif

A325 (N)

797

970

+22%

School Hill

479

479

0%

A325 (S)

549

731

+33%

Total

1825

2180

+19%

A325 (N)

1190

1508

+27%

School Hill

233

233

0%

A325 (S)

563

669

+19%

Total

5636

2410

+21%

The capacity assessments, summarised above, indicate that the A325 (N) and A325 (S) arms of the junction would require physical mitigation worksto improve capacity.

5.2.4

Drawing 00900001/GA/008 showsthe initial mitigation design (Option 1) for the miniroundabout. Nearside kerbline re-alignment on the A325 (N) and A325 (S) armshas enabled the entry widthsto be increased with the aim of improving capacity at these approaches. At the A325 (N) arm the entry width hasbeen increased from 4.0 metresat present to 5.4 metresand from the current 3.6 metresto 5.4 metresat the A325 (S) arm.

5.2.5

Capacity assessments were undertaken based upon the proposed measuresset out within drawing 00900001/GA/008 to evaluate the impact of the proposed improvementson the operation of the junction. The assessment results indicated that the Option 1 design would continue to operate worse than 2026 baseline conditionson both the A325 (N) and A325 (S) arms in both the AM and PM peakperiodsif proposed development Scenario 2 were implemented. The full Option 1 capacity assessment outputsare contained within Appendix C of thisreport.

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5.2.6

As the proposed measureswithin Option 1 were not sufficient to appropriately mitigate the junction against the traffic impact of the ‘worst case’ development Scenario 2, a further mitigation option wasconsidered at the roundabout. Drawing 00900001/GA/009 showsthe revised mitigation design (Option 2) for the roundabout. The proposed mitigation measures within Option 2 comprise the further re-alignment of the nearside kerblineson the A325 (N) and A325 (S) arms of the junction.

5.2.7

The re-aligned kerblinesintended to increase entry widthsat the over-capacity approaches to the mini-roundabout and, therefore, to increase capacity, represent the maximum achievable with the current junction arrangement within the public highway boundary given the constrained land availability surrounding the junction.

5.2.8

Capacity assessments were undertaken based upon the proposed measuresset out within drawing 00900001/GA/009 to evaluate the impact of the proposed improvementson the operation of the junction. The assessment results indicated that the Option 2 design would continue to operate worse than 2026 baseline conditionson both the A325 (N) and A325 (S) arms in both the AM and PM peakperiodsif proposed development Scenario 2 were implemented. The full Option 2 capacity assessment outputs are contained within Appendix C of thisreport.

5.2.9

As the proposed measures within Option 2 were not sufficient to appropriately mitigate the junction against the traffic impact of the ‘worst case’ development Scenario 2, a further mitigation option wasconsidered at the junction. Asthe previousmitigation optionshave maximised the existing mini-roundabout arrangement within available public highway land, any further physical improvementswould require the acquisition of surrounding private land for the junction to be accommodated. It isanticipated that the purchase of private land would be at considerable cost and, therefore, unviable at thisstage in mitigating the traffic impacts of the Whitehill Bordon Eco-town development only.

5.2.10

Drawing 00900001/GA/010 showsthe revised mitigation design (Option 3) for the junction. It was decided, due to the constrained nature of the junction and after a review of the forecast traffic flows, that a signalised junction would be an appropriate form of junction in this location. The proposed signalsarrangement incorporatessingle lane approacheson each of the arms and a short (2 PCU) right turn storage facility for vehicles turning from the A325 (S) into School Hill so as not to blockstraight ahead traffic. It should be noted that within the Option 3 proposalsthe accessto the scrap metal merchants, currently served by the existing mini-roundabout, would be uncontrolled by the proposed traffic signal control. However, due to there being no vehicles using thisaccess during either peak highway period it is anticipated that the proposed arrangement would be acceptable.

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5.3

Rev ised Junction Operation

5.3.1

The revised Option 3 junction arrangement hasbeen assessed for capacity during weekday AM and PM peakhoursfor the 2026 proposed development scenariosusing LinSig v3 software. As LinSig requirestraffic data in the form of PCU’sthe traffic flowsincorporated within the previousARCADY assessments have been factored to represent PCU’sand incorporated within the model.

5.3.2

The method of control incorporated within the proposed signalised junction issummarised in Figure 5.4 below: Figure 5.4: Proposed A325/School Hill Signalised Junction – Method of Control Min: 7 2

Min: 7

A

1

B

C

6

5.3.3

48s

6

30s

As the signalised junction isa proposed arrangement the stage lengthshave been optimised within an overall cycle time of 90 seconds. Saturation flowshave been derived from the Transport Research Laboratory (TRL) Research Report 67 (RR67) valuesbased upon the geometric layout of the junction which has been measured from the design drawing.

5.3.4

Table 5.5 and Table 5.6 below provide a summary of the AM and PM peakforecast year capacity assessments of the junction in itsrevised form to allow a comparison against the operation of the existing arrangement. The full modelling inputsand capacity assessment outputsare contained within this report within Appendix C.

Table 5.5: Proposed A325/School Hill Signalised Junction – 2026 AM Peak Capacity Assessment Summary 2026 Baseline Link

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Flow

2026 Dev elopment Scenario 2 (75%/30%)

(Total)

Max RFC

A325 (N)

797

0.842

5.0

1021

86.0%

24.2

School Hill

479

0.651

1.8

485

87.1%

14.5

A325 (S)

549

1.100

36.0

755

64.7%

13.3

19

Flow

Max

(PCU)

DoS

Mean

Max Queue (v eh)

Max Q (v eh)


Table 5.6: Proposed A325/School Hill Signalised Junction – 2026 PM Peak Capacity Assessment Summary 2026 Baseline Link

5.3.5

Flow (Total)

Max RFC

Max Queue (v eh)

A325 (N)

1190

1.230

School Hill

233

A325 (S)

563

2026 Dev elopment Scenario 2 (75%/30%) Mean

Flow

Max

(PCU)

DoS

140.1

1541

101.2%

63.8

0.378

0.6

237

95.3%

11.2

0.865

5.6

696

46.5%

6.8

Max Q (v eh)

The capacity assessments summarised above indicate that the proposed measureswithin Option 3 would appropriately mitigate the junction against the ‘worst case’ traffic impact of the development proposals. The proposed arrangement would fully mitigate the junction during the AM peakperiod and would significantly improve the operation of the junction in the PM peakwhen compared with the existing arrangement within the 2026 baseline scenario.

5.3.6

It should also be noted that the resultsonly represent fixed time control of the signals. Further improvement to the operation of the junction could be achieved through the implementation of MOVA control, asadopted on a number of surrounding signalised junctions.

5.4

Junction Improv ement Cost Estimate

5.4.1

An indicative cost estimate hasbeen developed for the proposed Option 3 arrangement at the junction to mitigate the traffic impacts of the proposed development. A summary of the feasibility stage cost estimate for the proposed improvements iscontained within this report as Appendix C.

5.4.2

It is estimated that the proposed highway works at the A325/School Hill junction would cost approximately £127,000. It should be noted, however, that the cost estimate isonly indicative at this stage as they are based upon preliminary junction design. The cost estimate of the highway works may be subject to change at detailed design stage.

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6

A325/B3004 Junction

6.1

Junction Information

6.1.1

The A325/B3004 junction isa signalised T junction situated to the north of Bordon, within the borders of Hampshire.

6.1.2

The capacity of the junction has been assessed during weekday AM and PM peakhoursfor the 2026 baseline and 2026 proposed development scenarios, asset out within the Whitehill Bordon Eco-town Evidence Base Transport Assessment. The assessments indicate that the junction would operate within capacity during both peakperiods within the 2026 baseline. The junction would, however, operate close to or over full capacity during both the AM and PM peakhighway periodsin 2026 if either of the proposed development scenarioswere implemented. Table 6.1 and Table 6.2, below, provide a summary of the AM and PM peak forecast year capacity assessments of the junction in itscurrent form, respectively: Table 6.1: A325/B3004 Junction – 2026 AM Peak Capacity Assessment Summary 2026 Development Scenario 1 (50%/50%)

2026 Baseline Link

2026 Development Scenario 2 (75%/30%)

Flow (Total)

Max DoS

Mean Max Q (v eh)

Flow (Total)

Max DoS

Mean Max Q (v eh)

Flow (Total)

Max DoS

Mean Max Q (v eh)

A325 (N)

668

60.6%

8.0

1062

76.4%

21.9

1060

73.5%

18.0

A325 (S)

1281

94.4%

42.8

1512

110.5%

133.3

1669

116.2%

183.9

B3004

336

92.7%

12.5

366

108.9%

30.6

328

115.9%

35.7

Table 6.2: A325/B3004 Junction – 2026 PM Peak Capacity Assessment Summary 2026 Baseline Link

2026 Development Scenario 1 (50%/50%)

2026 Development Scenario 2 (75%/30%)

Flow (Total)

Max DoS

Mean Max Q (v eh)

Flow (Total)

Max DoS

Mean Max Q (v eh)

Flow (Total)

Max DoS

Mean Max Q (v eh)

A325 (N)

1105

89.0%

33.2

1309

100.4%

63.1

1518

114.7%

160.5

A325 (S)

775

62.5%

13.6

860

66.7%

16.7

853

64.9%

15.7

B3004

382

88.5%

13.7

376

101.1%

21.4

401

114.7%

43.7

6.1.3

The above tablesindicate that the A325 (S) and B3004 armsof the junction would operate significantly over capacity during the AM peakand the A325 (N) and B3004 armsduring the PM peak within both of the 2026 forecast year development scenarios.

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6.2

Design Rationale

6.2.1

The proposed mitigation feasibility design optionsare shown within drawings 00900001/GA/011 - 00900001/GA/013, contained within Appendix D of thisreport. The proposed measuresat this junction are intended to fully mitigate against background traffic growth and the traffic impactsof the proposed development in forecast year 2026.

6.2.2

The capacity assessments, summarised in Table 6.1 and Table 6.2, above, indicate that all arms of the junction would require physical mitigation worksto improve capacity. Initially the MOC of the signalswas analysed to determine whether any improvement could be made without the need for physical mitigation. The existing MOC of the signalsat the junction, however, was considered to be efficient and without scope for significant improvement.

6.2.3

Drawing 00900001/GA/011 showsthe initial mitigation design (Option 1) for the junction. The stopline on the B3004 arm of the roundabout hasbeen relocated further towards the junction whilst still accommodating appropriate physical vehicle movementsonto the B3004 from the A325. The relocation of the stopline isintended to increase the stacking capacity for left turning traffic at the B3004 arm and also to reduce intergreen timeswithin the MOC of the junction.

6.2.4

Capacity assessments were undertaken based upon the proposed measuresset out within drawing 00900001/GA/011 to evaluate the impact of the proposed improvementson the operation of the junction. The assessment results indicated that the Option 1 design would continue to operate over capacity on the A325 (S) and B3004 armsof the junction in the AM peakand on the A325 (N) and B3004 armsduring the PM peakif either proposed development scenario were implemented. The full Option 1 capacity assessment outputsare contained within Appendix D of thisreport.

6.2.5

As the proposed measureswithin Option 1 were not sufficient to appropriately mitigate the junction against forecast 2026 traffic conditions, a further mitigation option wasconsidered at the junction. Drawing 00900001/GA/012 showsthe revised mitigation design (Option 2) for the junction. The proposed mitigation measureswithin Option 2 comprise the relocation of the stopline on the B3004 arm, asset out within Option 1, and the addition of two lane exits on both A325 armsof the junction. Thiswould enable the offside right turn lane on the A325 (N) arm to be converted to ‘ahead and right’ and the nearside left only lane on the A325 (S) arm to be converted to an ‘ahead and left’ lane. Additional non-blocking stacking capacity for right turning traffic from the A325 (N) to the B3004 would be provided in the centre of the junction to accommodate 3 PCU’swaiting for gapsin oncoming traffic.

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6.2.6

Capacity assessments were undertaken based upon the proposed measuresset out within drawing 00900001/GA/012 to evaluate the impact of the proposed improvementson the operation of the junction. The assessment results indicated that the Option 2 design would continue to operate over capacity on all armsof the junction in the AM peakbut would operate within capacity during the PM peak if either proposed development scenario were implemented. The full Option 2 capacity assessment outputsare contained within Appendix D of thisreport.

6.2.7

As the proposed measureswithin Option 2 were not sufficient to appropriately mitigate the junction against forecast 2026 traffic conditions, a further mitigation option wasconsidered at the junction. Drawing 00900001/GA/013 showsthe revised mitigation design (Option 3) for the junction. The proposed mitigation measureswithin Option 3 comprise the relocation of the stopline on the B3004 arm and the addition of two lane exitson both A325 arms, asset out within Options1 & 2, and the further addition of a dedicated right turn lane on the A325 (N) arm and a dedicated left turn lane on the A325 (S) arm. Furthermore, the existing Pickets Hill access adjacent to the junction would be converted to a left-in/left-out arrangement only. Alternative accessto Picketts Hill and Smithy Lane could be provided via High Thicket Road, Old Lane and Heath Hill from the north and via Frensham Lane from the south.

6.3

Rev ised Junction Operation

6.3.1

The revised Option 3 junction arrangement has been assessed for capacity during weekday AM and PM peakhoursfor the 2026 proposed development scenarios.

6.3.2

The MOC of the junction within the proposed Option 3 junction arrangement remainsthe same as existing. It should be noted that the two straight ahead laneson both of the A325 arms of the junction have been modelled asinfinitely long as, due to limitationswithin LinSig software, an infinitely long lane can only have one short lane associated with it. The dedicated left and right turn laneshave been modelled asshort lanes, therefore, meaning the straight ahead laneshave been modelled asinfinitely long. Asshown within drawing 00900001/GA/013, the nearside straight ahead lane on the A325 (N) arm has a capacity of approximately 11 PCU’sand the centre straight ahead lane on the A325 (S) arm hasa capacity of approximately 13 PCU’s. Thisneedsto be considered when analysing the results of the capacity assessments undertaken on the revised junction arrangement.

6.3.3

Table 6.3 and Table 6.4 below provide a summary of the AM and PM peakforecast year capacity assessments of the junction in itsrevised form to allow a comparison against the operation of the existing arrangement. The full modelling inputsand capacity assessment outputsare contained within thisreport within Appendix D.

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Table 6.3: Rev ised A325/B3004 Junction – 2026 AM Peak Capacity Assessment Summary 2026 Development Scenario 1 (50%/50%)

2026 Baseline Link

2026 Development Scenario 2 (75%/30%)

Flow (Total)

Max DoS

Mean Max Q (v eh)

Flow (Total)

Max DoS

Mean Max Q (v eh)

Flow (Total)

Max DoS

Mean Max Q (v eh)

A325 (N)

668

60.6%

8.0

1062

48.6%

8.3

1060

77.4%

8.3

A325 (S)

1281

94.4%

42.8

1512

79.7%

22.6

1669

84.2%

27.7

B3004

336

92.7%

12.5

366

79.4%

9.3

328

82.6%

8.7

Table 6.4: Rev ised A325/B3004 Junction – 2026 PM Peak Capacity Assessment Summary 2026 Baseline Link

2026 Development Scenario 1 (50%/50%)

2026 Development Scenario 2 (75%/30%)

Flow (Total)

Max DoS

Mean Max Q (v eh)

Flow (Total)

Max DoS

Mean Max Q (v eh)

Flow (Total)

Max DoS

Mean Max Q (v eh)

A325 (N)

1105

89.0%

33.2

1309

67.4%

18.4

1518

76.8%

24.5

A325 (S)

775

62.5%

13.6

860

51.5%

10.0

853

50.0%

9.4

B3004

382

88.5%

13.7

376

66.9%

9.2

401

75.4%

10.8

6.3.4

The above tablesindicate that the Option 3 improvements to the junction would result in all arms of the junction operating within capacity during both the AM and PM peakhighway periodsif either 2026 proposed development scenarioswere implemented. The proposed arrangement would fully mitigate the junction during both the AM and PM peakperiodsand would improve the operation of the junction when compared with the existing arrangement within the 2026 baseline scenario.

6.3.5

It should be noted that operation of the A325 (N) and A325 (S) arms of the junction would potentially be slightly worse than indicated above due to maximum queue lengthsexceeding the physical stacking capacity of the dedicated right turn and dedicated left turn lanes causing one of the straight ahead lanesto be blocked by queuing traffic, however this providesa reasonable comparative assessment between the with and without development scenarios.

6.4

Junction Improv ement Cost Estimate

6.4.1

An indicative cost estimate hasbeen developed for the proposed improvement works at the junction to mitigate the traffic impactsof the proposed development. A summary of the feasibility stage cost estimate for the proposed improvements iscontained within thisreport as Appendix D.

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6.4.2

It is estimated that the proposed highway worksat the A325/B3004 junction would cost approximately ÂŁ100,000. It should be noted, however, that the cost estimate isonly indicative at this stage as they are based upon preliminary junction design. The cost estimate of the highway works may be subject to change at detailed design stage.

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7

B3004/Paper Mill Lane Junction

7.1

Junction Information

7.1.1

The B3004/Paper Mill Lane junction isa staggered crossroads priority junction situated to the North East of Bordon on the outskirtsof the town of Alton in Hampshire.

7.1.2

The capacity of the junction hasbeen assessed during weekday AM and PM peakhoursfor the 2026 baseline and 2026 proposed development scenarios, as set out within the Whitehill Bordon Eco-town Evidence Base Transport Assessment. The assessments indicate that the junction would operate at or over full capacity during the AM peakwithin the 2026 baseline and within either proposed development scenariosin 2026. Furthermore, the assessments indicate that the junction would operate near to full capacity within the PM peakperiod if the ‘worst case’ proposed development Scenario 2 were implemented. Table 7.1, below, providesa summary of the critical AM peakforecast year capacity assessments of the junction in itscurrent form:

Table 7.1: B3004/Paper Mill Lane Junction – 2026 AM Peak Capacity Assessment Summary 2026 Baseline Link

2026 Development Scenario 1 (50%/50%)

Flow (Total)

Max RFC

Max Queue (v eh)

Flow (Total)

Max RFC

B3004 (E)

630

0.831

6.04

679

0.867

7.91

Ashdell Road

315

1.772

75.66

315

2.347

Paper Mill Lane

477

0.894

9.80

501

B3004 (N)

292

1.594

56.69

297

7.1.3

2026 Dev elopment Scenario 2 (75%/30%)

Max Flow Queue (Total) (v eh)

Max RFC

Max Queue (v eh)

835

0.907

12.14

99.76

315

7.985

175.50

0.894

10.12

519

0.916

10.24

1.883

73.02

316

3.169

115.74

The above table indicatesthat both the Ashdell Road and B3004 (N) armsof the junction would operate significantly over capacity during the AM peakperiod in 2026 within baseline conditionsand if either proposed development scenarioswere implemented. Furthermore, both the remaining arms, the B3004 (E) and Paper Mill Lane, would operate close to full capacity during the AM peak within all forecast year scenarios.

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7.2

Design Rationale

7.2.1

A proposed double mini-roundabout scheme for the junction, produced by Waterman Boreham on behalf of Tesco in March 2010, hasbeen provided by HCC, together with associated ARCADY assessments, to be assessed in forecast year traffic conditions. The proposed arrangement is shown within Waterman Boreham drawing 208337/48 rev B, contained within thisreport asAppendix E.

7.3

Rev ised Junction Operation

7.3.1

The revised junction arrangement hasbeen assessed for capacity during weekday AM and PM peakhours for the 2026 baseline and 2026 proposed development scenarios. Table 7.2 below providesa summary of the critical AM peakforecast year capacity assessments of the junction in itsrevised form to allow a comparison against the operation of the existing arrangement. The full capacity assessment outputsare contained within thisreport within Appendix E.

Table 7.2: Rev ised B3004/Paper Mill Lane Junction – 2026 AM Peak Capacity Assessment Summary 2026 Development 2026 Dev elopment Scenario 1 (50%/50%) Scenario 2 (75%/30%)

2026 Baseline Junction

North

South

7.3.2

Link Flow (Total)

Max RFC

Max Queue (v eh)

Flow (Total)

Max RFC

Max Queue Flow (Total) (v eh)

Max RFC

Max Queue (v eh)

B3004 (N)

292

0.47

0.89

297

0.49

0.96

316

0.53

1.12

Internal link (West)

700

0.74

0.00

749

0.76

0.00

905

0.80

0.00

Paper Mill Lane

477

0.85

5.05

501

0.91

7.55

519

0.92

8.51

B3004 (E)

630

1.00

17.60

679

1.07

35.47

835

1.31

129.09

Ashdell Road

315

0.49

0.95

315

0.50

0.99

315

0.52

1.05

Internal link (East)

680

0.80

0.00

709

0.83

0.00

746

0.87

0.00

The above table indicatesthat the proposed revised junction layout would operate at or above full capacity in the AM peakperiod 2026 within the baseline and proposed development scenarios.

7.3.3

When the capacity assessment results are compared with the forecast operation of the existing junction arrangement, the proposed junction showsa significant improvement, particularly at the B3004 (N) and Ashdell Road arms.

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7.4

Junction Improv ement Cost Estimate

7.4.1

An indicative cost estimate has been developed for the proposed double mini-roundabout junction arrangement. A summary of the feasibility stage cost estimate for the proposed improvementsiscontained within thisreport asAppendix E.

7.4.2

It is estimated that the proposed highway worksat the B3004/Paper Mill Lane junction would cost approximately ÂŁ26,000. It should be noted, however, that the cost estimate isonly indicative at this stage as they are based upon preliminary junction design. The cost estimate of the highway works may be subject to change at detailed design stage.

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8

A325/Tesco Access/Woolmer Way Junction

8.1

Junction Information

8.1.1

The A325/Tesco Access/Woolmer Way junction isa signalised crossroadssituated within Bordon town centre in Hampshire.

8.1.2

The capacity of the junction hasbeen assessed during weekday AM and PM peakhoursfor the 2026 baseline and 2026 proposed development scenarios, as set out within the Whitehill Bordon Eco-town Evidence Base Transport Assessment. The assessments indicate that the junction would operate over capacity during the PM peakwithin the 2026 baseline scenario and close to full capacity within the PM peakof either proposed development scenariosin 2026. The junction would, however, operate within capacity during the AM peakperiod within all 2026 forecast year scenarios. Table 8.1 below, providesa summary of the critical PM peakforecast year capacity assessments of the junction in itscurrent form:

Table 8.1: A325/Tesco Access/Woolmer Way Junction – 2026 PM Peak Capacity Assessment Summary 2026 Development Scenario 1 (50%/50%)

2026 Baseline Link

2026 Development Scenario 2 (75%/30%)

Flow (Total)

Max DoS

Mean Max Q (v eh)

Flow (Total)

Max DoS

Mean Max Q (v eh)

Flow (Total)

Max DoS

Mean Max Q (v eh)

A325 (N)

876

108.0%

61.3

718

95.3%

23.1

720

95.5%

23.3

Tesco Access

359

110.8%

29.2

356

92.8%

10.8

355

92.7%

10.8

A325 (S)

622

59.9%

8.4

294

83.1%

5.7

301

84.3%

5.9

Woolmer Way

90

60.6%

2.9

24

15.4%

0.6

24

15.4%

0.6

8.1.3

The above table indicatesthat, although the implementation of either 2026 development scenario would result in a significant improvement at the junction due to the provision of the Inner Relief Road, the A325 (N) and Tesco Access arms of the junction would operate close to full capacity during the PM peakperiod.

8.2

Design Rationale

8.2.1

The capacity assessments, summarised above, indicate that the A325 (N) and Tesco Access arms of the junction would need minor improvement in 2026 if either proposed development were implemented. Due to the constrained nature of the junction, situated in the town centre, and further to a site visit it wasconsidered that there islimited scope for physical improvement at the critical A325 (N) and Tesco Access arms of the junction.

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8.2.2

The traffic signalsat the junction are currently controlled by CablelessLinking Facility (CLF) whereby the controller containsfixed green timesfor each traffic signal stage. The efficiency of the traffic signal operation at the junction could be improved through the implementation of MOVA, which attemptsto continuously optimise the timing of the signalsdepending on the traffic demand. It isrecognised that MOVA operated junctionson street will achieve an increase in capacity and a reduction in delay when compared to a fixed time operation due to the continuousprocess of optimisation throughout the model period.

8.2.3

The proposed mitigation feasibility design isshown within drawing 00900001/GA/014 contained within thisreport asAppendix F. The proposal comprisesthe provision of MOVA detector loopson the approaches to the junction and the implementation of MOVA within the traffic signal controller(s).

8.3

Rev ised Junction Operation

8.3.1

The implementation of MOVA control at the junction cannot be appropriately assessed within LinSig due to limitationsin the modelling software only allowing fixed time signal timingsto be incorporated. Because MOVA respondsdynamically to variationsin vehicle arrival rates, there is currently no analytical technique for predicting in advance the extent of improvement at a particular junction. Transport Research Laboratory (TRL)/Department of Transport (DoT) research has shown that MOVA reducesdelaysby an average of 13% compared to earlier vehicle actuated (VA) systems. In the context of capacity, TRL have advocated that the capacity improvement isapproximately 1/3 of the delay savings(‘Modelling MOVA control We know it’s good, but just how good isit?’ – D.Meehan, 2003). It is, therefore, considered in the context of the A325/Tesco Access/Woolmer Way junction and the current CLF signal control that an increase in capacity in the range of 5%-7% could be anticipated at the junction.

8.3.2

As stated above, the MOVA controller continuously optimisesthe amount of green time afforded to each stage within the MOC depending on the traffic demand. Thisprocess would result in a more efficient operation of the junction when compared with the fixed time traffic model used to assess the junction for the 2026 forecast year within LinSig. It is, therefore, considered that the implementation of MOVA control at the junction would result in the junction operating within capacity during both AM and PM peakhighway periodsin 2026 if either proposed development scenario were implemented.

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8.4

Junction Improv ement Cost Estimate

8.4.1

An indicative cost estimate has been developed for the proposed improvement works at the junction to mitigate the traffic impactsof the proposed development. A summary of the feasibility stage cost estimate for the proposed improvements iscontained within this report as Appendix F.

8.4.2

It is estimated that the proposed highway works at the A325/Tesco Access/Woolmer Way junction would cost approximately ÂŁ38,000. It should be noted, however, that the cost estimate isonly indicative at thisstage asthey are based upon preliminary junction design. The cost estimate of the highway works may be subject to change at detailed design stage.

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9

A325/Liphook Rd/Firgrove Rd Roundabout

9.1

Junction Information

9.1.1

The A325/LiphookRd/Firgrove Rd junction isa standard roundabout situated to the South of Bordon town centre within the borders of Hampshire.

9.1.2

The capacity of the roundabout hasbeen assessed during weekday AM and PM peakhours for the 2026 baseline and 2026 proposed development scenarios, as set out within the Whitehill Bordon Eco-town Evidence Base Transport Assessment. The assessments indicate that the junction would operate within capacity during both peak periodswithin the 2026 baseline. The junction would, however, operate over capacity during both the AM and PM peakhighway periodsin 2026 if either of the proposed development scenarioswere implemented. Table 9.1 and Table 9.2, below, provide a summary of the AM and PM peak forecast year capacity assessments of the junction in itscurrent form, respectively:

Table 9.1: A325/Liphook Rd/Firgrov e Rd Roundabout – 2026 AM Peak Capacity Assessment Summary 2026 Baseline Link

2026 Development 2026 Dev elopment Scenario 1 (50%/50%) Scenario 2 (75%/30%)

Max Queue Flow (Total) (v eh)

Max RFC

Max Queue (v eh)

Flow (Total)

Max RFC

1033

1.263

132.5

1012

1.304 145.7

0.5

334

0.428

0.7

377

0.501

1.0

0.908

8.3

950

0.978

17.6

1002

0.983

19.1

0.367

0.6

300

0.453

0.8

392

0.577

1.3

Flow (Total)

Max RFC

A325 (N)

735

0.865

5.8

Liphook Road

289

0.342

A325 (S)

916

Firgrov e Road

265

Max Queue (v eh)

Table 9.2: A325/Liphook Rd/Firgrov e Rd Roundabout – 2026 PM Peak Capacity Assessment Summary 2026 Baseline Link

Max Flow Queue (Total) (v eh)

Max RFC

Max Queue (v eh)

Flow (Total)

Max RFC

Max Queue (v eh)

975

1.111

63.8

1006

1.178

93.8

0.3

270

0.350

0.5

337

0.427

0.7

0.562

1.3

816

0.824

4.4

871

0.904

8.0

0.351

0.5

298

0.406

0.7

348

0.504

1.0

Flow (Total)

Max RFC

A325 (N)

781

0.844

5.0

Liphook Road

201

0.243

A325 (S)

577

Firgrov e Road

319

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2026 Development 2026 Dev elopment Scenario 1 (50%/50%) Scenario 2 (75%/30%)

32


9.1.3

The above tablesindicate that the A325 (N) arm of the junction of the junction would operate significantly over capacity during both the AM and PM peakhighway periodsin 2026 if either proposed development scenarioswere implemented. Furthermore, the A325 (S) arm of the junction would operate close to full capacity, particularly during the AM peak, in 2026 if either proposed development scenarioswere implemented.

9.2

Design Rationale

9.2.1

The proposed mitigation feasibility design optionsare shown within drawings 00900001/GA/015 - 00900001/GA/017, contained within Appendix G of thisreport. The proposed measuresat this junction are intended to fully mitigate against background traffic growth and the traffic impactsof the proposed development in forecast year 2026.

9.2.2

The capacity assessments summarised in Table 9.1 and Table 9.2, above, indicate that the A325 (N), in particular, and A325 (S) armsof the junction would require physical mitigation works to improve capacity. Only the Firgrove Road arm of the junction currently achieves adequate deflection on approach to the roundabout.

9.2.3

Drawing 00900001/GA/015 showsthe initial mitigation design (Option 1) for the roundabout. Nearside kerbline re-alignment on the A325 (N) and A325 (S) armsenabled the entry widths and flare lengthsto be increased with the aim of improving capacity at these approaches. At the A325 (N) arm the entry width hasbeen increased from 4.2 metresat present to 6.0 metresand the flare length increased from 0.0 metresto 9.4 metres. At the A325 (S) arm the entry width hasbeen increased from 4.8 metresat present to 5.5 metresand the flare length increased from 0.0 metresto 6.7 metres.

9.2.4

Capacity assessments were undertaken based upon the proposed measures set out within drawing 00900001/GA/015 to evaluate the impact of the proposed improvementson the operation of the junction. The assessment results indicated that the Option 1 design, although showing an improvement on the A325 (N) arm, would operate over capacity on both the A325 (N) and A325 (S) armsin the AM peakand close to full capacity in the PM peakif either proposed development scenarioswere implemented. It should also be noted that where capacity improvementshave been gained on the A325 arms, the operation of the LiphookRoad and Firgrove Road armshave deteriorated. The full Option 1 capacity assessment outputsare contained within Appendix G of thisreport.

9.2.5

As the proposed measureswithin Option 1 were not sufficient to appropriately mitigate the junction against the traffic impactsof the proposed Whitehill Bordon Eco-town development, a further mitigation option was considered at the roundabout. Drawing 00900001/GA/016 shows the revised mitigation design (Option 2) for the roundabout. The proposed mitigation measures within Option 2 comprise the further re-alignment of the nearside kerblineson all arms of the junction.

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9.2.6

The re-aligned kerblinesintended to increase entry widths and flare lengthson the approachesto the roundabout represent the maximum achievable with the current junction arrangement within the public highway boundary given the constrained land availability surrounding the junction.

9.2.7

Capacity assessments were undertaken based upon the proposed measures set out within drawing 00900001/GA/016 to evaluate the impact of the proposed improvementson the operation of the junction. The assessment results indicated that the Option 2 design would operate close to full capacity on the A325 (N) and A325 (S) armsin both the AM and PM peakperiodsif either proposed development scenarioswere implemented. The full Option 2 capacity assessment outputsare contained within Appendix G of thisreport.

9.2.8

As the proposed measureswithin Option 2 were not sufficient to appropriately mitigate the junction against the traffic impactsof the proposed Whitehill Bordon Eco-town development, a further mitigation option wasconsidered at the roundabout. Drawing 00900001/GA/017 shows the revised mitigation design (Option 3) for the roundabout. The proposed mitigation measures within Option 3 comprise the enlargement of the inscribed circle diameter (ICD) and circulatory carriageway of the roundabout and further realignment of kerblines to increase the entry widthsand flare lengthson the approaches to the junction.

9.2.9

The ICD of the roundabout has been increased from 28.0 metresto 32.0 metresand the circulatory carriageway has been increased form 6.0 metresto 9.0 metres. In order to accommodate the increase in size of the roundabout and the adjacent 2.0 metre wide footway around itsedge, reinforced embankmentswill need to be provided where the proposal extendsover the extentsof the existing structure above the disused railway line. The enlargement of the roundabout enablesthe entry widthsand flare lengthson each of the roundabout approachesto be increased.

9.3

Rev ised Junction Operation

9.3.1

The revised junction arrangement hasbeen assessed for capacity during weekday AM and PM peakhours for the 2026 baseline and 2026 proposed development scenarios. Table 9.3 and Table 9.4 below provide a summary of the AM and PM peakforecast year capacity assessments of the junction in itsrevised form to allow a comparison against the operation of the existing arrangement. The full capacity assessment outputsare contained within this report within Appendix G.

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Table 9.3: Rev ised A325/Liphook Rd/Firgrov e Rd Roundabout – 2026 AM Peak Capacity Assessment Summary 2026 Baseline Link

2026 Development 2026 Dev elopment Scenario 1 (50%/50%) Scenario 2 (75%/30%)

Max Flow Queue (Total) (v eh)

Max RFC

Max Queue (v eh)

Flow (Total)

Max RFC

Max Queue (v eh)

1033

0.825

4.5

1012

0.842

5.0

0.5

334

0.564

1.3

377

0.685

2.1

0.908

8.3

950

0.732

2.7

1002

0.738

2.8

0.367

0.6

300

0.507

1.0

392

0.644

1.8

Flow (Total)

Max RFC

A325 (N)

735

0.865

5.8

Liphook Road

289

0.342

A325 (S)

916

Firgrov e Road

265

Table 9.4: Rev ised A325/Liphook Rd/Firgrov e Rd Roundabout – 2026 PM Peak Capacity Assessment Summary 2026 Baseline Link

Max Queue Flow (Total) (v eh)

Max RFC

Max Queue (v eh)

Flow (Total)

Max RFC

Max Queue (v eh)

975

0.732

2.7

1006

0.772

3.3

0.3

270

0.417

0.7

337

0.531

1.1

0.562

1.3

816

0.615

1.6

871

0.675

2.0

0.351

0.5

298

0.443

0.8

348

0.555

1.2

Flow (Total)

Max RFC

A325 (N)

781

0.844

5.0

Liphook Road

201

0.243

A325 (S)

577

Firgrov e Road

319

9.3.2

2026 Development 2026 Dev elopment Scenario 1 (50%/50%) Scenario 2 (75%/30%)

The above tablesindicate that the Option 3 improvements to the junction would result in all arms of the junction operating within capacity during both the AM and PM peakhighway periodsif either 2026 proposed development scenarioswere implemented.

9.4

Junction Improv ement Cost Estimate

9.4.1

An indicative cost estimate has been developed for the proposed improvement works at the junction to mitigate the traffic impactsof the proposed development. A summary of the feasibility stage cost estimate for the proposed improvements iscontained within this report as Appendix G.

9.4.2

It is estimated that the proposed highway works at the A325/LiphookRoad/Firgrove Road roundabout would cost approximately £126,000. It should be noted, however, that the cost estimate isonly indicative at thisstage as they are based upon preliminary junction design. The cost estimate of the highway works may be subject to change at detailed design stage.

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10

A325/Petersfield Road Roundabout

10.1

Junction Information

10.1.1

The A325/Petersfield Road junction isa standard roundabout situated to the South of Bordon within the bordersof Hampshire.

10.1.2

The capacity of the roundabout hasbeen assessed during weekday AM and PM peakhours for the 2026 baseline and 2026 proposed development scenarios, asset out within the Whitehill Bordon Eco-town Evidence Base Transport Assessment. The assessments indicate that the junction would operate within capacity during both peakperiodswithin the 2026 baseline. The junction would, however, operate over or near to full capacity during the AM peakperiod in 2026 if either of the proposed development scenarios were implemented but within capacity during the PM peak period. Table 10.1 below, therefore, providesa summary of the critical AM peakforecast year capacity assessments of the junction in its current form:

Table 10.1: A325/Petersfield Rd Roundabout – 2026 AM Peak Capacity Assessment Summary 2026 Baseline Link

2026 Development Scenario 1 (50%/50%)

Flow (Total)

Max RFC

Max Queue (v eh)

Flow (Total)

Max RFC

A325 (N)

896

0.787

3.6

1136

1.018

31.3

A325 (E)

854

0.533

1.1

942

0.617

Petersfield Road

137

0.169

0.2

145

0.193

10.1.3

2026 Dev elopment Scenario 2 (75%/30%)

Max Flow Queue (Total) (v eh)

Max RFC

Max Queue (v eh)

1323

1.175

121.6

1.6

944

0.627

1.7

0.2

148

0.195

0.2

The above table indicatesthat the A325 (N) arm of the junction would operate over capacity during the AM peakperiod if either 2026 proposed development scenarioswere implemented.

10.2

Design rationale

10.2.1

The proposed mitigation feasibility design isshown within drawing 00900001/GA/018 contained within this report as Appendix H.

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10.2.2

The capacity resultsabove indicate that the A325 (N) arm of the roundabout would require physical mitigation worksto improve capacity. The arm, at present, provides the minimum standard deflection on approach to the roundabout in order to reduce vehicle speeds. Any realignment of the nearside kerbline would result in inadequate deflection on the approach being provided, therefore, any improvementsto increase the entry width and/or effective flare length, the two most significant factorsaffecting capacity at a roundabout entry, would need to be undertaken on the off-side of the approach.

10.2.3

The centreline of the arm has been relocated further to the west, whilst still providing adequate width for vehiclesexiting the roundabout at this arm, and the physical deflection island has been reduced and realigned. These proposed measuresenable to entry width of the arm to be increased from 7.3 metresat present to 9.5 metres; the maximum achievable at the roundabout asthe entry width should not exceed the width of the circulatory carriageway. Furthermore, the effective flare length of the arm isincreased from 6.0 metres at present to 12.0 metres.

10.2.4

The existing deflection island accommodatesa 2.75 metre wide informal crossing facility for pedestrians providing dropped kerbsand tactile paving. The proposed reduced central island providesa 2.1 metre wide informal crossing facility again providing dropped kerbs and tactile paving to aid pedestrians. It isanticipated, due to the rural location of junction and the small number of residencesin close proximity, that pedestrian flowsat the junction would be minimal and the proposed crossing facility adequate.

10.3

Rev ised Junction Operation

10.3.1

The revised junction arrangement hasbeen assessed for capacity during weekday AM and PM peakhours for the 2026 proposed development scenarios. Table 10.2 below providesa summary of the critical AM peakforecast year capacity assessments of the junction in its revised form to allow a comparison against the operation of the existing arrangement. The full capacity assessment outputsare contained within thisreport within Appendix H.

Table 10.2: Rev ised A325/Petersfield Rd Roundabout – 2026 AM Peak Capacity Assessment Summary 2026 Baseline Link

2026 Development Scenario 1 (50%/50%)

Flow (Total)

Max RFC

Max Queue (v eh)

Flow (Total)

Max RFC

A325 (N)

896

0.787

3.6

1136

0.729

2.6

A325 (E)

854

0.533

1.1

942

0.551

Petersfield Road

137

0.169

0.2

145

0.163

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2026 Dev elopment Scenario 2 (75%/30%)

Max Flow Queue (Total) (v eh)

Max RFC

Max Queue (v eh)

1323

0.841

5.1

1.2

944

0.571

1.3

0.2

148

0.165

0.2


10.3.2

The above table indicatesthat the improvementsto the junction would result in all armsof the junction operating within capacity during the AM peakperiod if either 2026 proposed development scenarioswere implemented. During the PM peakperiod, the improved junction would operate within capacity.

10.4

Junction Improv ement Cost Estimate

10.4.1

An indicative cost estimate has been developed for the proposed improvement works at the junction to mitigate the traffic impactsof the proposed development. A summary of the feasibility stage cost estimate for the proposed improvements iscontained within this report as Appendix H.

10.4.2

It is estimated that the proposed highway works at the A325/Petersfield Road roundabout would cost approximately ÂŁ20,000. It should be noted, however, that the cost estimate is only indicative at thisstage as they are based upon preliminary junction design. The cost estimate of the highway works may be subject to change at detailed design stage.

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11

A325/A3 (Eastbound) Slip-roads

11.1

Junction Information

11.1.1

The A325/A3 (Eastbound) slip-roadsjunction isa standard roundabout situated to the South of Bordon within the bordersof Hampshire. Asthe junction incorporatesslip-roadsonto the A3 and, therefore, the HighwaysAgency (HA) network, the HA also hold an interest in the operation of the junction.

11.1.2

The capacity of the roundabout hasbeen assessed during weekday AM and PM peakhours for the 2026 baseline and 2026 proposed development scenarios, asset out within the Whitehill Bordon Eco-town Evidence Base Transport Assessment. The assessments indicate that the junction would operate within capacity during both peakperiods within the 2026 baseline. The junction would, however, operate over or near to full capacity during the AM peakperiod in 2026 if either of the proposed development scenarioswere implemented but within capacity during the PM peakperiod. Table 11.1 below providesa summary of the critical AM peakforecast year capacity assessments of the junction in its current form:

Table 11.1: A325/A3 Slip-Roads Roundabout – 2026 AM Peak Capacity Assessment Summary 2026 Development 2026 Dev elopment Scenario 1 (50%/50%) Scenario 2 (75%/30%)

2026 Baseline Link Flow (Total)

Max RFC

Max Queue (v eh)

Flow (Total)

Max RFC

Max Queue (v eh)

Flow (Total)

Max RFC

Max Queue (v eh)

A325 (N)

777

0.751

2.9

953

0.940

11.4

1044

1.007

25.9

A3 On-slip (Exit)

-

-

-

-

-

-

-

-

-

A325 (S)

175

0.158

0.2

142

0.129

0.1

194

0.177

0.2

A3 Off-slip

869

0.565

1.3

994

0.650

1.8

944

0.623

1.6

11.1.3

The above table indicatesthat the A325 (N) arm of the junction would operate near to full capacity during the AM peakperiod in the forecast year 2026 if development Scenario 1 were implemented; and would operate over capacity if development Scenario 2 were implemented.

11.2

Design Rationale

11.2.1

The proposed mitigation feasibility design isshown within drawing 00900001/GA/019 contained within thisreport asAppendix I.

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11.2.2

The capacity resultsabove indicate that the A325 (N) arm of the roundabout would require physical mitigation worksto improve capacity. The arm currently providesappropriate deflection on the approach to the junction to reduce vehicle speeds. The nearside kerbline has been realigned to achieve an increased entry width from 7.0 metres up to 7.7 metres and an increased effective flare length from 2.3 metresat present to 9.0 metres; whilst still providing appropriate deflection on the approach.

11.2.3

The current arrangement at the A325 (S) and A3 Off-slip armsof the junction provides inadequate deflection on the approachesto the junction. However, it should be noted that the proximity of the overbridge to the A325 (S) entry to the roundabout would make improvementsto achieve the desired deflection at thisarm difficult.

11.3

Rev ised Junction Operation

11.3.1

The revised junction arrangement hasbeen assessed for capacity during weekday AM and PM peakhours for the 2026 proposed development scenarios. Table 11.2 below providesa summary of the critical AM peakforecast year capacity assessments of the junction in its revised form to allow a comparison against the operation of the existing arrangement. The full capacity assessment outputsare contained within thisreport within Appendix I.

Table 11.2: A325/A3 Slip-Roads Roundabout – 2026 AM Peak Capacity Assessment Summary 2026 Development 2026 Dev elopment Scenario 1 (50%/50%) Scenario 2 (75%/30%)

2026 Baseline Link Flow (Total)

Max RFC

Max Queue (v eh)

Flow (Total)

Max RFC

Max Queue (v eh)

Flow (Total)

Max RFC

Max Queue (v eh)

A325 (N)

777

0.751

2.9

953

0.717

2.5

1044

0.768

3.2

A3 On-slip (Exit)

-

-

-

-

-

-

-

-

-

A325 (S)

175

0.158

0.2

142

0.121

0.1

194

0.166

0.2

A3 Off-slip

869

0.565

1.3

994

0.613

1.6

944

0.588

1.4

11.3.2

The above table indicatesthat the improvementsto the junction would result in all armsof the junction operating within capacity during the AM peakperiod if either 2026 proposed development scenarioswere implemented.

11.4

Junction Improv ement Cost Estimate

11.4.1

An indicative cost estimate hasbeen developed for the proposed improvement works at the junction to mitigate the traffic impactsof the proposed development. A summary of the feasibility stage cost estimate for the proposed improvementsiscontained within this report as Appendix I.

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11.4.2

It is estimated that the proposed highway worksat the A325/A3 (Eastbound) Slip-roads roundabout would cost approximately £24,000. It should be noted, however, that the cost estimate isonly indicative at thisstage asthey are based upon preliminary junction design. The cost estimate of the highway works may be subject to change at detailed design stage.

11.5

Slip-road Geometry and Collision Analysis

11.5.1

At a project team meeting held on 5 th April 2011, the HA requested that the geometry of the A3 on-slip be considered against appropriate Design Manual for Roadsand Bridges(DMRB) standards and alongside collision data to understand whether the existing geometry isa causal factor to collisions.

11.5.2

The slip road geometry hasbeen considered against DMRB TD 40/94 ‘Design Standardsfor Compact Connector Roads’ and DMRB 22/06 ‘Layout of Grade Separated Junctions’. The minimum radius on the slip hasbeen measured from ordnance survey mapping as36m. The minimum radius on the slip meetsthe absolute minimum requirementswithin both standards stated above.

11.5.3

Personal injury collision data wasprovided by Hampshire County Council for the period March 2006 to February 2011. The data provided wasrestricted to the narrative text describing each collision, other information usually recorded at the scene; weather, road surface condition (wet/dry), skidding, speed, causal factors etc. were not included. Unless mentioned in the narrative these factorscould not be included in the analysis, limiting the scope of the analysis. The collision data and further analysisiscontained within thisreport within Appendix I.

11.5.4

The collision data showsthat there were 9 collisions(3 slight, 6 serious) within the 5 year period. Of these, five were on the A3 (westbound) carriageway, two on the A325 (N) approximately 50m north of the roundabout and two on the A3 (eastbound) carriageway. The collision locationsand a brief summary of each collision are shown on drawing 00900001/GA/020 within Appendix I.

11.5.5

The two collisionson the A325 (N) occurred in approximately the same location 50m north of the roundabout. At thispoint the approach to the roundabout ison a right hand radiusof approximately 120m. Both involved motorcyclistsapproaching the roundabout losing control and colliding with the near side safety barrier. Asthere isno indication in the collision report of vehicles in front of the motorcycliststhissuggests both were due to a lackof awareness of the bend or excess speed rather than the presence of the roundabout.

11.5.6

Of the collisionson the A3 (westbound) carriageway, one collision involved a broken down vehicle some distance from the junction; and four involved lossof control on both entry (1) and exit (3) slip roadsnear the splitter island.

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11.5.7

Of the two collisionson the A3 (eastbound) carriageway, one involved a collision with a broken down vehicle at some distance from the junction. The other involved a vehicle on the slip road merging with the A3 traffic colliding with a vehicle on the main carriageway.

11.5.8

The collision data indicatesthat only one accident occurred in proximity to the A3 (eastbound) on-slip within the study period. It is, therefore, considered that there isno significant safety issue associated with the existing geometry of the slip road.

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12

A3/B3006 Roundabout

12.1

Junction Information

12.1.1

The A3/B3006 roundabout issituated South West of Bordon within the bordersof Hampshire. However, asthe A3 forms part of the HighwaysAgency (HA) network the junction isunder the authority of the HA.

12.1.2

The capacity of the roundabout hasbeen assessed during weekday AM and PM peakhours for the 2026 baseline and 2026 proposed development scenarios, asset out within the Whitehill Bordon Eco-town Evidence Base Transport Assessment. The assessments indicate that the junction would operate over capacity during both the AM and PM peakperiodswithin the 2026 baseline and within either proposed development scenariosin 2026. Table 12.1 and Table 12.2, below, provide a summary of the AM and PM peakforecast year capacity assessments of the junction in its current form, respectively:

Table 12.1: A3/B3006 Roundabout – 2026 AM Peak Capacity Assessment Summary 2026 Development Scenario 1 (50%/50%)

2026 Baseline Link

2026 Dev elopment Scenario 2 (75%/30%)

Flow (Total)

Max RFC

Max Queue (v eh)

Flow (Total)

Max RFC

Max Queue (v eh)

Flow (Total)

Max RFC

Max Queue (v eh)

B3006 (N)

506

0.712

2.4

561

0.809

4.0

665

0.948

11.3

A3 (E)

1743

0.945

13.5

1930

1.076

86.7

2028

1.226

218.3

B3006 (S)

170

0.348

0.5

311

0.664

1.9

311

0.702

2.3

A3 (W)

2095

1.093

109.7

2189

1.202

216.3

2234

1.222

240.6

Table 12.2: A3/B3006 Roundabout – 2026 PM Peak Capacity Assessment Summary 2026 Baseline Link

2026 Development Scenario 1 (50%/50%)

2026 Dev elopment Scenario 2 (75%/30%)

Flow (Total)

Max RFC

Max Queue (v eh)

Flow (Total)

Max RFC

Max Queue (v eh)

Flow (Total)

Max RFC

Max Queue (v eh)

B3006 (N)

903

1.231

99.3

924

1.354

140.2

935

1.434

164.8

A3 (E)

1930

1.126

130.5

2008

1.157

165.1

2020

1.152

163.5

B3006 (S)

127

0.319

0.5

128

0.316

0.5

138

0.336

0.5

A3 (W)

1707

0.851

5.5

1785

0.893

7.8

1887

0.946

14.0

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12.1.3

The above tablesindicate that the A3 (E) and A3 (W) arms of the junction would operate near to or over full capacity within all 2026 forecast year scenariosduring the AM peak period. The B3006 (N) and A3 (E) arms of the junction would operate significantly over capacity within all 2026 forecast year scenariosduring the PM peak.

12.1.4

A Scheme Identification Study (SIS), undertaken in 2011 on behalf of the HA, identified a number of potential mitigation options for the roundabout with the aim of reducing congestion in light of the anticipated opening of the Hindhead Tunnel in Mid-2011. Only potential options which would not likely exceed the Local NetworkManagement Schemes threshold were considered.

12.1.5

The study promotesthree potential options, from an initial total of ten, which are summarised below: Option B – full-time signalised roundabout Option D – removal of the existing at-grade junction (likely significant impact on surrounding network) Option F – B3006 Overbridge

12.1.6

Of the three HA promoted schemesabove, HCC were yet to select a preferred scheme at the time of writing. The report setsout an aim of identifying a HCC and HA agreed scheme by Summer 2011. Thisstudy, therefore, aimsto develop an interim proposal to mitigate against the traffic impact of the Whitehill Bordon Eco-town.

12.2

Design Rationale

12.2.1

The proposed mitigation feasibility design optionsare shown within drawings 00900001/GA/021 - 00900001/GA/023, contained within Appendix J of thisreport.

12.2.2

The proposed measuresat this junction are intended to mitigate against the traffic impactsof the proposed development only. The proportional increase in forecast year traffic flow through the junction of the proposed development scenarioscompared with the 2026 baseline are shown in Table 12.3 below:

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Table 12.3: A3/B3006 Roundabout – Traffic Impact of Dev elopment Proposals

Peak Period

AM

PM

12.2.3

Arm

2026 Baseline

2026 Development Scenario 1 (50%/50%)

2026 Development Scenario 2 (75%/30%)

Flow

Flow

%Dif

Flow

%Dif

B3006 (N)

506

561

+11%

665

+31%

A3 (E)

1743

1930

+11%

2028

+16%

B3006 (S)

170

311

+83%

311

+83%

A3 (W)

2095

2189

+4%

2234

+7%

Total

4514

4991

+11%

5238

+16%

B3006 (N)

903

924

+2%

935

+4%

A3 (E)

1930

2008

+4%

2020

+5%

B3006 (S)

127

128

+1%

138

+9%

A3 (W)

1707

1785

+5%

1887

+11%

Total

4667

4845

+4%

4980

+7%

The capacity assessments summarised above indicate that the B3006 (N), A3 (E) and A3 (W) arms of the junction would require physical mitigation works to improve capacity. Furthermore, at present the B3006 (N), A3 (E) and A3 (W) arms do not achieve the minimum standard deflection in order to slow vehicle speedson the approach to the roundabout.

12.2.4

Drawing 00900001/GA/021 showsthe initial mitigation design (Option 1) for the roundabout. Kerbline realignment enabled the entry widthsand effective flare lengthsto be increased at each of the over capacity approachesto the roundabout. At the B3006 (N) arm the entry width hasbeen increased from 7.3 metresat present to 9.1 metresand the flare length increased from 18.4 metresto 22.0 metres. At the A3 (E) arm the entry width hasbeen increased from 8.0 metres at present to 9.6 metresand the flare length increased from 0.0 metresto 17.5 metres. At the A3 (W) arm the entry width hasbeen increased from 8.0 metresat present to 10.0 metresand the flare length increased from 0.0 metresto 20.0 metres.

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12.2.5

Capacity assessments were undertaken based upon the proposed measuresset out within drawing 00900001/GA/021 to evaluate the impact of the proposed improvementson the operation of the junction. The full Option 1 capacity assessment outputsare contained within Appendix J of this report. The assessment results indicated that the Option 1 design would continue to operate worse than 2026 baseline conditionson the A31 (E) and B3006 (S) arms in the AM peakperiod if development Scenario 2 were implemented.

12.2.6

As the proposed measureswithin Option 1 were not sufficient to appropriately mitigate the junction against the traffic impact of the ’worst case’ development Scenario 2, a further mitigation option wasconsidered at the roundabout. Drawing 00900001/GA/022 showsthe revised mitigation design (Option 2) for the roundabout. The proposed mitigation measures within Option 2 comprise the removal of white lining and hatching within the roundabout and on the approachesto further increase entry widthsand flare lengths at the junction and the provision of concentric spiral roadmarkingswithin the circulatory carriageway.

12.2.7

Further capacity assessments were undertaken based upon the proposed measuresset out within drawing 00900001/GA/022 to evaluate the impact of the proposed improvementson the operation of the junction. The full Option 2 capacity assessment outputsare contained within Appendix J of thisreport. The assessment results indicated that the Option 2 design would operate worse than 2026 baseline conditions on the B3006 (N), A31 (E) and B3006 (S) arms in the AM peakperiod if development scenario 2 were implemented. Furthermore, it was deemed that further minor tweaksto the existing junction arrangement to increase capacity would result in further reducing deflection at the over capacity approacheswhich are already sub-standard at present.

12.2.8

Therefore, a further mitigation option wasconsidered at the roundabout comprising the realignment of the A31 (E) and A31 (W) approachesto the junction, the incorporation of a subsidiary deflection island on the A31 (E) arm; and the provision of concentric spiral roadmarkingswithin the circulatory carriageway. Drawing 00900001/GA/023 showsthe revised mitigation design (Option 3) for the roundabout. The re-alignment of the A31 approachesto the roundabout, taking land from the existing central reservesto tighten the angle of approach, enable the entry widthsand flare lengthsto be further increased whilst also improving deflection at these arms.

12.2.9

Following observationsat the junction during a site visit it wasdecided to incorporate a subsidiary deflection island on the A3 (E) arm of the junction in order to further improve deflection on the approach. It wasobserved on site that there was a potential riskof vehicles overturning when negotiating the tight radiuson the south-eastern section of the roundabout circulatory; particularly asthissection corner of the roundabout hasan adverse camber.

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12.3

Rev ised Junction Operation

12.3.1

The revised junction arrangement hasbeen assessed for capacity during weekday AM and PM peakhours for the 2026 baseline and 2026 proposed development scenarios. Table 12.4 and Table 12.5 below provide a summary of the AM and PM peakperiod forecast year capacity assessments of the junction in itsrevised form to allow a comparison against the operation of the existing arrangement. The full capacity assessment outputsare contained within this report within Appendix J.

Table 12.4: Rev ised A3/B3006 Roundabout – 2026 AM Peak Capacity Assessment Summary 2026 Development Scenario 1 (50%/50%)

2026 Baseline Link

2026 Dev elopment Scenario 2 (75%/30%)

Flow (Total)

Max RFC

Max Queue (v eh)

Flow (Total)

Max RFC

Max Queue (v eh)

Flow (Total)

Max RFC

Max Queue (v eh)

B3006 (N)

506

0.712

2.4

561

0.747

2.8

665

0.877

6.1

A3 (E)

1743

0.945

13.5

1930

0.854

5.6

2028

0.972

20.3

B3006 (S)

170

0.348

0.5

311

0.593

1.4

311

0.847

4.4

A3 (W)

2095

1.093

109.7

2189

0.979

23.8

2234

0.997

32.7

Table 12.5: Rev ised A3/B3006 Roundabout – 2026 PM Peak Capacity Assessment Summary 2026 Baseline Link

2026 Development Scenario 1 (50%/50%)

2026 Dev elopment Scenario 2 (75%/30%)

Flow (Total)

Max RFC

Max Queue (v eh)

Flow (Total)

Max RFC

Max Queue (v eh)

Flow (Total)

Max RFC

Max Queue (v eh)

B3006 (N)

903

1.231

99.3

924

1.074

45.5

935

1.136

68.6

A3 (E)

1930

1.126

130.5

2008

0.960

16.9

2020

0.956

16.0

B3006 (S)

127

0.319

0.5

128

0.449

0.8

138

0.468

0.9

A3 (W)

1707

0.851

5.5

1785

0.732

2.7

1887

0.775

3.4

12.3.2

The capacity assessments summarised above indicate that the proposed measureswithin Option 3 would appropriately mitigate the junction against the traffic impact of the Whitehill Bordon Eco-town development proposalsin 2026 during both the AM and PM peakhighway periods. It should be noted that the operation of the B3006 (N) and B3006 (S) armsof the junction would operate slightly worse when compared with baseline conditions during the AM peakin 2026 if development Scenario 2 were implemented, however, both armswould still operate within capacity.

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12.4

Junction Improv ement Cost Estimate

12.4.1

An indicative cost estimate has been developed for the proposed improvement works at the junction to mitigate the traffic impactsof the proposed development. A summary of the feasibility stage cost estimate for the proposed improvements iscontained within this report as Appendix J.

12.4.2

It is estimated that the proposed highway works at the A3/B3006 Roundabout, asshown within proposed Option 3, would cost approximately ÂŁ98,000. It should be noted, however, that the cost estimate isonly indicative at thisstage asthey are based upon preliminary junction design. The cost estimate of the highway works may be subject to change at detailed design stage.

12.5

Collision Analysis

12.5.1

PIC data was provided by Hampshire County Council for the period March 2006 to February 2011. The data provided wasrestricted to the narrative text describing each collision, other information usually recorded at the scene; weather, road surface condition (wet/dry), skidding, speed, causal factorsetc. were not included. Unless mentioned in the narrative these factors could not be included in the analysis, limiting the scope of the analysis. The collision data and further analysisiscontained within Appendix J of thisreport.

12.5.2

The collision data showsthat there were 19 collisions(18 slight, 1 serious) over the five year period. Of these, eighteen were within approximately 100m of the junction. The remaining two were remote from the junction, one on the A3 (W) carriageway and one on the B3006 (S) arm of the junction. The collision locationsand a brief summary of each collision are shown on drawing 00900001/GA/024 within Appendix J.

12.5.3

The collisionsat the roundabout fall into one clear group and 4 other looser groups. The clear group isa group of five collisionson the A3 (W) approach to the roundabout, these all involve rear end collisionswith slow moving or stationary vehicles. There isa further cluster of three collisionson the A3 (E) exit, two of which were single vehicle collisionsinvolving loss of control with no clear causal factors; the third involved a vehicle overturning after striking a stationary vehicle.

12.5.4

On the A3 (E) entry there were two collisionsrecorded which appear to be related to queuing traffic, one a straight forward rear end shunt, the second involving a vehicle losing control overtaking another vehicle on the approach to the roundabout. The later case suggeststhat excess speed was a factor but thiswas not recorded.

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12.5.5

The other collision groupingsare all on the circulatory carriageway, two between the B3006 (N) entry and the A3 (W) exit and three on the southern part of the roundabout. Although three of these involved vehiclesleaving the roundabout, at different locations, and all occurred on the circulatory carriageway, there isno other obviouscorrelation between these collisions.

12.5.6

At this roundabout extensive road marking and signing hasbeen provided. These are all of a type which suggests excess speed on the A3 approacheshasbeen a long term problem and that overturning hasalso been an issue. On the A3 (W) approach there isstill clearly a problem on the approach but it isunclear from the data provided if speed wasa factor in any of these collisions. On the A3 (E) approach one collision suggestsexcess speed may still an issue.

12.5.7

There isno record of overturning still being an issue at the roundabout. The two overturning collisionswhich have occurred were as a result of collision with stationary vehicles. However, from observation goodsvehiclesare still at some risk of overturning. In particular they have some difficulty negotiating the tight radiuson the south-eastern part of the circulatory carriageway due, in part, to the adverse camber.

12.5.8

There isclearly an existing problem at thisjunction that needsto be addressed. The proposed development would increase traffic flowsat thisjunction by 11% to 12% which would exacerbate the problems. The Option 3 mitigation proposalsto increase capacity at the junction have taken into account the current and past safety record and should directly address current safety issues at the junction.

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13

B3004/Oakhanger Road Junction

13.1

Junction Information

13.1.1

The B3004/Oakhanger Road junction isa priority T junction situated to the North West of Bordon within Hampshire.

13.1.2

The capacity of the junction has been assessed during weekday AM and PM peakhoursfor the 2026 baseline and 2026 proposed development scenarios, as set out within the Whitehill Bordon Eco-town Evidence Base Transport Assessment. The assessments indicate that the junction would operate within capacity during both the AM and PM peakperiodswithin the 2026 baseline and if Scenario 1 isimplemented and that no improvement isrequired. The assessment does however show that the junction would operate over capacity during the AM peakif proposed development Scenario 2 were implemented. Table 13.1 below providesa summary of the critical AM peakforecast year capacity assessment of the junction in its current form:

Table 13.1: B3004/Oakhanger Rd Junction – 2026 AM Peak Capacity Assessment Summary 2026 Dev elopment Scenario 2 (75%/30%)

2026 Baseline Link

13.1.3

Flow (Total)

Max RFC

Max Queue (v eh)

Flow (Total)

Max RFC

Max Queue (v eh)

B3004 (E)

403

-

-

428

-

-

Oakhanger Road

340

0.782

3.3

568

1.292

83.1

B3004 (W)

378

0.251

0.5

465

0.478

1.2

The above table indicatesthat the Oakhanger Road arm of the junction would operate significantly over capacity during the AM peakin 2026 if proposed development Scenario 2 were implemented. The remaining armsof the junction operate comfortably within capacity.

13.2

Design Rationale

13.2.1

The proposed mitigation feasibility design optionsare shown within drawings 00900001/GA/025 - 00900001/GA/026, contained within Appendix K of thisreport.

13.2.2

The above assessments indicate that the Oakhanger Road arm of the junction would require physical mitigation worksto improve capacity. However, due to the constrained nature of the junction, and in particular the Oakhanger Road arm, it was considered that an alternative form of junction would be appropriate to mitigate the ‘worst case’ traffic impacts of the proposed development.

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13.2.3

Drawing 00900001/GA/025 showsthe initial mitigation design (Option1) for the junction. The proposed mitigation measureswithin Option 1 comprise the conversion of the existing priority junction to a small standard roundabout arrangement. The roundabout incorporates the minimum acceptable ICD for a standard roundabout of 28 metresand the re-alignment of the B3004 in order to achieve appropriate deflection on the approachesto the roundabout to slow vehicle speeds.

13.2.4

Capacity assessments were undertaken based upon the proposed measures set out within drawing 00900001/GA/025 to evaluate the impact of the proposed improvementson the operation of the junction. The full Option 1 capacity assessment outputsare contained within Appendix K of this report. The assessment results indicated that the proposed Option 1 roundabout arrangement would operate within capacity on all armsduring the AM peakin 2026 if proposed development Scenario 2 were implemented.

13.2.5

It was considered, however, that highway works associated with the implementation of a roundabout and the required re-alignment of the existing B3004 would be significant and potentially prohibitive to Option 1 representing a viable option for the mitigation of the junction. A further alternative option was, therefore, developed for the mitigation of the ’worst case’ traffic impactsof the proposed Whitehill Bordon Eco-town development at the junction.

13.2.6

Drawing 00900001/GA/026 showsthe initial mitigation design (Option 2) for the junction. The proposed mitigation measureswithin Option 2 comprise the implementation of traffic signal control. The physical geometry of the junction would remain asexisting but would require the addition of appropriate roadmarkings, ducting and traffic signal controller(s).

13.3

Rev ised Junction Operation

13.3.1

The revised Option 2 signalised junction arrangement hasbeen assessed for capacity during the critical weekday AM peakfor the 2026 proposed development scenario 2 using LinSig v3 software. As LinSig requirestraffic data in the form of PCU’sthe traffic flowsincorporated within the previousARCADY assessments have been factored to represent PCU’sand incorporated within the model.

13.3.2

The method of control incorporated within the proposed signalised junction issummarised in Figure 13.2 below:

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Figure 13.2: Proposed B3004/Oakhanger Rd Signalised Junction – Method of Control 1

Min: 7 2

B

B

Min: 0 3

Min: 7

A

C

6

13.3.3

61s

0

0s

6

47s

As the signalised junction isa proposed arrangement without any pedestrian phasesthe stage lengthshave been optimised within an overall cycle time of 120 seconds. Saturation flows have been derived from the Transport Research Laboratory (TRL) Research Report 67 (RR67) valuesbased upon the geometric layout of the junction which has been measured from design drawing.

13.3.4

Table 13.3 below provides a summary of the AM peakforecast year capacity assessment of the junction in itsrevised form to allow a comparison against the operation of the existing arrangement. The full modelling inputs and capacity assessment outputsare contained within this report within Appendix K.

Table 13.3: Proposed B3004/Oakhanger Rd Signalised Junction – 2026 AM Peak Capacity Assessment Summary 2026 Dev elopment Scenario 2 (75%/30%)

2026 Baseline Link

13.3.5

Flow (Total)

Max RFC

Max Queue (v eh)

B3004 (E)

403

-

Oakhanger Road

340

B3004 (W)

378

Mean

Flow

Max

(PCU)

DoS

-

439

44.6%

9.5

0.782

3.3

577

85.8%

20.3

0.251

0.5

475

89.8%

18.6

Max Q (v eh)

The capacity assessment summarised above indicatesthat the proposed Option 2 signalised junction would appropriately mitigate the junction against the traffic impact of the Whitehill Bordon Eco-town development proposalsScenario 2 in 2026 during the AM peak highway period.

13.3.6

It should also be noted that the resultsonly represent fixed time control of the signals. Further improvement to the operation of the junction could be achieved through the implementation of MOVA control, asadopted on a number of surrounding signalised junctions.

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13.4

Junction Improv ement Cost Estimate

13.4.1

An indicative cost estimate has been developed for the proposed Option 2 junction arrangement at the junction to mitigate the traffic impactsof the proposed development Scenario 2. A summary of the feasibility stage cost estimate for the proposed improvements is contained within thisreport as Appendix K.

13.4.2

It is estimated that the proposed highway works at the B3004/Oakhanger Road junction would cost approximately ÂŁ33,000. It should be noted, however, that the cost estimate is only indicative at thisstage as they are based upon preliminary junction design. The cost estimate of the highway works may be subject to change at detailed design stage.

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14

A325/B3002 Station Road Junction

14.1

Junction Information

14.1.1

The A325/B3002 junction isa signalised crossroadssituated to the North of Bordon town centre in Hampshire.

14.1.2

The capacity of the junction hasbeen assessed during weekday AM and PM peakhours for the 2026 baseline and 2026 proposed development scenarios, as set out within the Whitehill Bordon Eco-town Evidence Base Transport Assessment. The assessments indicate that the junction would operate within capacity during both the AM and PM peakperiodswithin the 2026 baseline and Scenario 1 and that no improvement would be required. The assessment doeshowever show that the junction would operate over capacity during the AM peakif proposed development Scenario 2 were implemented. Table 14.1 below providesa summary of the critical AM peakforecast year capacity assessment of the junction in its current form:

Table 14.1: A325/B3002 Station Rd Junction – 2026 AM Peak Capacity Assessment Summary 2026 Baseline Link Flow (Total)

14.1.3

Max DoS

2026 Dev elopment Scenario 2 (75%/30%)

Mean Max Q (v eh)

Flow (Total)

Max DoS

Mean Max Q (v eh)

A325 (N)

505

92.2%

20.6

158

29.4%

4.3

B3002 Lindford Road

638

102.8%

37.1

835

128.9%

130.0

A325 (S)

747

104.1%

50.9

987

128.6%

151.9

B3002 Station Road

289

102.8%

21.0

397

127.9%

61.5

The above table indicatesthat the B3002 Lindford Road, A325 (S) and B3002 Station Road arms of the junction would operate significantly over capacity during the AM peakin 2026 if proposed development Scenario 2 were implemented.

14.2

Design Rationale

14.2.1

The proposed mitigation feasibility design optionsare shown within drawings 00900001/GA/027 - 00900001/GA/029, contained within Appendix L of thisreport.

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14.2.2

The above capacity assessments indicate that the B3002 Lindford Road, A325 (S) and B3002 Station Road armsof the junction would require physical mitigation works to improve capacity.

14.2.3

Drawing 00900001/GA/027 showsthe initial mitigation design (Option 1) for the junction. The proposed measurescomprise the provision of an additional dedicated right turn lane on the B3002 Lindford Road and an additional dedicated left turn lane on the B3002 Station Road arm of the junction. It was considered that an additional dedicated left turn lane on the A325 (S) arm would not be appropriate due to the low traffic demand undertaking thismovement.

14.2.4

Capacity assessments were undertaken based upon the proposed measures set out within drawing 00900001/GA/027 to evaluate the impact of the proposed improvementson the operation of the junction. The full Option 1 capacity assessment outputsare contained within Appendix L of this report. The assessment results indicate that the proposed Option 1 design would continue to operate near to full capacity on the B3002 Lindford Road, A325 (S) and B3002 Station Road armsof the junction during the AM peakin 2026 if proposed development Scenario 2 were implemented.

14.2.5

As the proposed measureswithin Option 1 were not sufficient to appropriately mitigate the junction against the traffic impact of the ‘worst case’ development Scenario 2, a further mitigation option wasconsidered. Drawing 00900001/GA/028 showsthe revised mitigation design (Option 2) for the junction. The proposed mitigation measureswithin Option 2 comprise the increase in stacking capacity within the dedicated left turn laneson the B3002 Lindford Road and B3002 Station Road arms; and within the dedicated right turn lane on the A325 (S) arm of the junction. The proposed Option 2 mitigation design representsthe maximum possible increase to the junction in itscurrent form (signalised cross-roads) within the existing public highway boundary.

14.2.6

Further capacity assessments were undertaken based upon the proposed measures set out within drawing 00900001/GA/028 to evaluate the impact of the proposed improvementson the operation of the junction. The full Option 2 capacity assessment outputsare contained within Appendix L of thisreport. The assessment results indicate that the Option 2 design would continue to operate near to full capacity on the B3002 Lindford Road, A325 (S) and B3002 Station Road armsof the junction during the AM peakin 2026 if proposed development Scenario 2 were implemented.

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14.2.7

As the proposed measureswithin Option 2 were not sufficient to appropriately mitigate the junction against the traffic impact of the ’worst case’ development Scenario 2, a further mitigation option wasconsidered at the junction. The previousmitigation optionshave maximised the existing junction arrangement within available public highway land, any further physical improvementswould require the acquisition of surrounding private land for the junction to be accommodated. It isanticipated that the purchase of private land would be at considerable cost and, therefore, unviable at thisstage in mitigating the traffic impacts of the Whitehill Bordon Eco-town development.

14.2.8

Drawing 00900001/GA/029 showsthe revised mitigation design (Option 3) for the junction. It was decided, in light of the forecast traffic flowsbeing well balanced acrossthe armsof the junction and the available public highway land, that a standard roundabout would be an appropriate form of junction in thislocation. The proposed roundabout incorporates an ICD of 40 metresand the re-alignment of all armson approach to the junction.

14.3

Rev ised Junction Operation

14.3.1

The revised Option 3 roundabout arrangement hasbeen assessed for capacity during the critical weekday AM peakhour for the 2026 proposed development scenario 2. Table 14.2 below providesa summary of the critical AM peakforecast year capacity assessments of the junction in itsrevised form to allow a comparison against the operation of the existing arrangement. The full capacity assessment outputsare contained within thisreport within Appendix L.

Table 14.2: Proposed A325/B3002 Station Rd Roundabout – 2026 AM Peak Capacity Assessment Summary 2026 Baseline Link Flow (Total)

14.3.2

Max DoS

2026 Dev elopment Scenario 2 (75%/30%)

Mean Max Q (v eh)

Flow (Total)

Max RFC

Max Queue (v eh)

A325 (N)

505

92.2%

20.6

146

0.126

0.1

B3002 Lindford Road

638

102.8%

37.1

803

0.543

1.2

A325 (S)

747

104.1%

50.9

950

0.722

2.5

B3002 Station Road

289

102.8%

21.0

272

0.502

1.0

The capacity assessment summarised above indicatesthat the proposed Option 3 roundabout junction arrangement would appropriately mitigate the junction against the traffic impact of the Whitehill Bordon Eco-town development proposalsin 2026 during the AM peak highway period.

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14.4

Junction Improv ement Cost Estimate

14.4.1

An indicative cost estimate has been developed for the proposed Option 3 junction arrangement at the junction to mitigate the traffic impactsof the proposed development Scenario 2. A summary of the feasibility stage cost estimate for the proposed improvements is contained within thisreport as Appendix L.

14.4.2

It is estimated that the proposed highway works at the A325/B3002 Station Road junction would cost approximately ÂŁ108,000. It should be noted, however, that the cost estimate is only indicative at thisstage as they are based upon preliminary junction design. The cost estimate of the highway works may be subject to change at detailed design stage.

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15

B3006/Petersfield Road Junction

15.1

Junction Information

15.1.1

The B3006/Petersfield Road junction isa priority junction situated South West of Bordon within Hampshire.

15.1.2

The capacity of the junction has been assessed during weekday AM and PM peakhoursfor the 2026 baseline and 2026 proposed development scenarios, asset out within the Whitehill Bordon Eco-town Evidence Base Transport Assessment. However, based upon a detailed site visit to the junction and re-measurement of the junction’sgeometry it wasdecided to undertake revised ‘worst case’ forecast year capacity assessments of the existing junction arrangement.

15.1.3

The revised capacity assessments indicate that the junction would operate within capacity during both the AM and PM peakperiods within the 2026 baseline and if Scenario 1 were implemented, but would operate close to full capacity during the AM peakif proposed development Scenario 2 were implemented. The full revised capacity assessment outputs are contained within this report within Appendix M. Table 15.1 below providesa summary of the critical AM peakforecast year revised capacity assessment of the junction in its current form:

Table 15.1: B3006/Petersfield Rd Junction – 2026 AM Peak Capacity Assessment Summary 2026 Dev elopment Scenario 2 (75%/30%)

2026 Baseline Link

15.1.4

Flow (Total)

Max RFC

Max Queue (v eh)

Flow (Total)

Max RFC

Max Queue (v eh)

B3006 (NW)

421

-

-

428

-

-

Petersfield Road

222

0.623

1.6

380

0.938

8.9

B3006 (S)

753

0.170

0.2

925

0.157

0.2

The above table indicatesthat the Petersfield Road arm of the junction would operate close to full capacity during the AM peak in 2026 if proposed development Scenario 2 were implemented. The remaining armsof the junction operate comfortably within capacity.

15.2

Design Rationale

15.2.1

The proposed mitigation feasibility design isshown within drawing 00900001/GA/030 contained within thisreport asAppendix M.

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15.2.2

The capacity resultsabove indicate that the Petersfield Road arm of the roundabout would require physical mitigation worksto improve capacity. The proposed mitigation measuresfor the junction comprise the re-alignment of the nearside kerbline on the Petersfield Road arm of the junction, to increase the flare length in order to enable two carsside by side at the give-way line. The deflection on the approach to the junction isprovided through the maintained nearside kerb build-out.

15.3

Rev ised Junction Operation

15.3.1

The revised junction arrangement hasbeen assessed for capacity during the weekday AM peakhour for the 2026 proposed development Scenario 2. Table 15.2 below providesa summary of the critical AM peakforecast year capacity assessments of the junction in its revised form to allow a comparison against the operation of the existing arrangement. The full capacity assessment outputsare contained within thisreport within Appendix M.

Table 15.2: Rev ised B3006/Petersfield Rd Junction – 2026 AM Peak Capacity Assessment Summary 2026 Dev elopment Scenario 2 (75%/30%)

2026 Baseline Link

15.3.2

Flow (Total)

Max RFC

Max Queue (v eh)

Flow (Total)

Max RFC

Max Queue (v eh)

B3006 (NW)

421

-

-

428

-

-

Petersfield Road

222

0.623

1.6

380

0.686

2.1

B3006 (S)

753

0.170

0.2

925

0.157

0.2

The above table indicatesthat the improvementsto the junction would result in all armsof the junction operating within capacity during the AM peakperiod if the ’worst case’ 2026 proposed development Scenario 2 were implemented.

15.4

Junction Improv ement Cost Estimate

15.4.1

An indicative cost estimate hasbeen developed for the proposed improvement works at the junction to mitigate the traffic impactsof the proposed development. A summary of the feasibility stage cost estimate for the proposed improvements iscontained within thisreport as Appendix M.

15.4.2

It is estimated that the proposed highway works at the B3006/Petersfield Road junction would cost approximately £18,000. It should be noted, however, that the cost estimate is only indicative at thisstage as they are based upon preliminary junction design. The cost estimate of the highway works may be subject to change at detailed design stage.

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16

Summary & Conclusions

16.1.1

The aim of the study wasto identify appropriate measuresto mitigate the potential traffic impactsof the proposed Whitehill Bordon Eco-town development on a number of key junctionson the surrounding road network. The key junctionsrequiring mitigation were identified within the associated Whitehill Bordon Eco-town Transport Assessment (TA).

16.1.2

The proposed measuresat each junction have been developed in order to mitigate against two alternative development scenariosbased on assumed levelsof car mode share and trip containment. Both scenariosincorporate the same quantum of development, as established within the TA, and the implementation of an inner relief road and traffic management measures on the existing A325 in the town centre.

16.1.3

For the identified junctionsunder the authority of Hampshire County Council the proposed measures are designed to fully mitigate the junction for the forecast year 2026 against background traffic growth, committed development traffic and predicted traffic generated by the Eco-town proposals. For the identified junctions under the authority of Surrey County Council and the Highways Agency the proposed measuresare intended to mitigate against the ‘worst case’ traffic impacts of the Eco-town development only, and do not seek to fully mitigate traffic conditionsin the future year.

16.1.4

Each identified junction hasbeen investigated individually and appropriate mitigation measures identified. The identified measuresare shown within preliminary stage engineering drawings; illustrating the design processand the preferred option(s) for each junction. The drawingsare supported by associated text describing the design process, revised junction assessments indicating the likely operation of the proposed measures; and cost estimatesto provide an approximate cost for the preferred mitigation option.

16.1.5

Appropriate mitigation measureshave been identified for each of the 13 junctionsin order that the impact of the proposed Eco-town can be ameliorated. Revised capacity assessments and cost estimatesfor the proposalshave been provided to allow the operational benefit of each option to be considered against cost to aid decision making processes.

16.1.6

Table 16.1 below provides a summary of the proposed measures and associated costs in order to appropriately mitigate the impactsof the Whitehill Bordon Eco-town proposals.

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Table 16.1: Junction Mitigation Proposals Summary Junction Location

16.1.7

Proposed Works

Works Cost

A31/B3001 Hickleys Corner (SCC)

Signal junction improvement including provision of pedestrian footbridge

£322,000

A31/A325 Coxbridge Roundabout (SCC)

Roundabout Improvement

£174,000

A325/School Hill Miniroundabout (SCC)

Replacement with Traffic signals

£127,000

A325/B3004 Junction (HCC)

Signal junction improvement

£100,000

B3004/Paper Mill Lane Junction (HCC)

Replacement with double Miniroundabout

£26,000

A325/Tesco Access/Woolmer Way Junction (HCC)

Implement MOVA

£38,000

A325/Liphook Road/Firgrov e Road Roundabout (HCC)

Roundabout Improvement

£126,000

A325/Petersfield Road Roundabout (HCC)

Roundabout Improvement

£20,000

B3004/Oakhanger Road Junction (HCC)

Replacement with Traffic signals

£86,000

A325/B3002 Station Road (HCC)

Replacement with Roundabout

B3006/Petersfield Road Junction (HCC)

Priority junction improvement

£18,000

A325/A3 (Eastbound) Slips (HA)

Roundabout Improvement

£24,000

A3/B3006 Roundabout (HA)

Roundabout Improvement

£98,000

£108,000

In conclusion, it isconsidered that there are no significant traffic issuesor ‘showstoppers’, at thisstage, associated with the mitigation of the identified junctions to prevent the allocation of the Whitehill Bordon Eco-town proposalswithin the Local Development FrameworkCore Strategy. It should be noted, however, that thisstudy has not considered the potential funding or priority of the proposed measuresbut hasaimed to identify that there are no physical barriersto the potential mitigation of the junctions in engineering terms.

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Appendix A:

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A

A31/Hickleys Corner Junction


Appendix B:

00900001/005

B

A31/A325 Coxbridge Roundabout


Appendix C:

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C

A325/School Hill Mini-Roundabout


Appendix D:

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D

A325/B3004 Junction


Appendix E:

00900001/005

E

B3004/Paper Mill Lane Junction


Appendix F:

A325/Tesco Access/Woolmer Way Junction

00900001/005

F


Appendix G:

A325/Liphook Road/Firgrove Road Roundabout

00900001/005

G


Appendix H:

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H

A325/Petersfield Road Roundabout


Appendix I:

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A325/A3 (Eastbound) Slip-roads

I


Appendix J :

00900001/005

J

A3/B3006 Roundabout


Appendix K:

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K

B3004/Oakhanger Road Junction


Appendix L:

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L

A325/B3002 Station Road Junction


Appendix M:

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M

B3006/Petersfield Road Junction

Junction Mitigation Report  

Whitehill Bordon Junction Mitigation Report

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