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The SANDAG Activity Activity--Based Travel Model

Institute of Traffic Engineers Luncheon Presentation April 1, 2010


Trip-Based Model Overview

Trip Generation

Trip Distribution

Mode Choice

Trip Assignment

Trip Productions (Pi) Zone

Pi

1

34

2

66

Trip Attractions (Aj) Zone

Aj

1

82

2

18

From Zone

To Zone 1

1

27

7

2

55

Total Aj

82

Mode

Trips (Tijm)

Route

Trips (Tijmr)

34

Auto

30

Route A

18

11

66

Transit

25

Route B

7

18

100

2

Total Pi

Institute of Traffic Engineers Luncheon April 1, 2010


Criticisms of Trip-Based Models • Lack of Behavioral Fidelity – The only model based on actual decision-making theory is mode choice (in most model systems)

• Aggregation Bias – No information on non-home-based trips – Each additional market segment (socio-economic category, trip purpose, time period) significantly increases runtime

• Lack of Policy Responsiveness – Time-of-day shifts – Socio-economic changes – Induced travel

Institute of Traffic Engineers Luncheon April 1, 2010


What is an Activity-Based Travel Model? • Travel is a derived demand – it results for the need for people to engage in activities outside the home. • Activity-based travel models attempt to replicate how people decide: – – – –

whether to travel where to travel to when to travel how to travel

• Activity-based travel models are based on behavioral decision-making theory • This makes them more suited to address policies that affect how people make travel decisions than trip-based models Institute of Traffic Engineers Luncheon April 1, 2010


Activity-Based Travel Models • Model travel by individuals – All important socio-economic characteristics are tracked explicitly – Micro-simulation used

• Model trips as part of tours – A series of trips beginning and ending at home or work (anchor locations) – Primary destination, intermediate stops – No more non-home-based trips!!

• Schedule tours into available time-windows – Consistent daily activity patterns that replicate survey data

Institute of Traffic Engineers Luncheon April 1, 2010


Complex Planning Issues Addressed with AB Models • • • • • • • •

Affects of transport policies on time-use Demographic changes & equity analysis Demand management policies (HOV, pricing) Changes in accessibilities Better interface with traffic simulation models Telecommuting Global transportation policies & taxation Evacuation planning Institute of Traffic Engineers Luncheon April 1, 2010


ABM: Tours and Trips Work-Based Tour Zone 1

Zone 3

Home-Based Work Trip

Non-Home-Based Trip

Non-Home-Based Trip

Work Tour Origin Home-Based Other Trip

Primary Origin Non-Home-Based Destination Trip

Zone 2

Zone 4

Primary Destination

Intermediate Stop

Data View: HH #

Per #

Tour #

Purp

Origin TAZ

Destin. TAZ

Outbound Stop1 TAZ

Return Stop1 TAZ

Mode

Subtour

Sub-Tour Destin.

1023

1

1

Work

1

3

0

2

Transit

Yes

4

Institute of Traffic Engineers Luncheon April 1, 2010


Activity-Based Models: Mode Consistency Work Tour Zone 1

Work-Based Tour Zone 3

Zone 2

Bus to Work = Drive alone not available for lunch

Institute of Traffic Engineers Luncheon April 1, 2010

Zone 4


Activity-Based Model: Micro-simulation • A synthetic population is created that represents the actual population • Travel is explicitly modeled for each person/household • Monte Carlo simulation is used instead of fractional probability aggregation: Discrete choices made for each traveler • Results are aggregated and: – Assigned to transport networks – Compiled into reports

Institute of Traffic Engineers Luncheon April 1, 2010


Activity-Based Model For San Diego Based on the CT-RAMP (Coordinated Travel – Regional Activity-based Modeling Platform) Family of Activity-Based Travel Demand Models •

• Main features: • Explicit intra-household interactions • Continuous temporal dimension (Half-hourly time periods) •Logit formulations for choice models •Sensitive to a wide range of socio-economic variables, transportation costs/accessibilities, and land-use changes •Java-based package for model implementation Institute of Traffic Engineers Luncheon April 1, 2010


Activity-Based Models In the United States Seattle Oregon Ohio San Francisco

Sacramento Lake Tahoe

NY Columbus

Denver

Bay Area

Los Angeles San Diego

Phoenix Atlanta

Developed by PB Developed by others CT-RAMP Family

(Atlanta model co-developed with MTC) Institute of Traffic Engineers Luncheon April 1, 2010


1. Population Synthesis 2. Long-term

3. Mobility

2.1. Usual workplace / school

3.1. Free Parking Eligibility

4. Daily

3.2. Car ownership

3.3. Transponder Ownership

4.1. Person pattern type & Joint Tour Indicator Nonmandatory

Mandatory

Home

Joint (household level)

Available time budget

Residual time

Individual Mandatory Tours

Joint NonMandatory Tours

Allocated Tours

4.2.1. Frequency 4.2.2. TOD

At-work sub-tours

4.3.1. Frequency

4.4.1. Frequency

4.3.2. Party

4.4.2. Allocation

Individual Discretionary Tours 4.5.1. Frequency

4.3.3. Participation

4.6.1. Frequency 4.6.2. Destination 4.6.3. TOD

4.3.4. Destination

4.4.3. Destination

4.5.2. Destination

4.3.5. TOD

4.4.4. TOD

4.5.3. TOD

5. Tour level 5.1. Tour mode

6. Trip level

5.2. Stop frequency

5.3. Stop location

5.4. Stop Departure

6.1. Trip mode 6.2. Auto parking 6.3. Assignment

Institute of Traffic Engineers Luncheon April 1, 2010

12

12


A relevant cartoon‌

Institute of Traffic Engineers Luncheon April 1, 2010


Activity Types TYPE

PURPOSE

DESCRIPTION

CLASSIFICATION

ELIGIBILITY

1

Work[1]

Working at regular workplace or work-related activities outside the home.

Mandatory

Workers and students

2

University

College +

Mandatory

Age 18+

3

High School

Grades 9-12

Mandatory

Age 14-17

4

Grade School

Grades K-8

Mandatory

Age 5-13

5

Escorting

Pick-up/drop-off passengers (auto trips only).

Maintenance

Age 16+

6

Shopping

Shopping away from home.

Maintenance

5+ (if joint travel, all persons)

7

Other Maintenance

Personal business/services, and medical appointments.

Maintenance

5+ (if joint travel, all persons)

8

Social/Recreational

Recreation, visiting friends/family.

Discretionary

5+ (if joint travel, all persons)

9

Eat Out

Eating outside of home.

Discretionary

5+ (if joint travel, all persons)

10

Other Discretionary

Volunteer work, religious activities.

Discretionary

5+ (if joint travel, all persons)

Institute of Traffic Engineers Luncheon April 1, 2010


Modes Choice

NonMotorized

Auto

Drive-Alone

DriveAlone Free

DriveAlone Pay

Shared-Ride 2

Shared 2 Free

Shared 2 Pay

Shared-Ride 3+

Shared 3+ Free

Walk

Shared 3+ Pay

• Explicit toll versus non-toll choice • Explicit treatment of line-haul transit modes

Transit

Bike

Drive-Transit

Walk-Transit

Walk-Local

Walk-BRT

Drive-Local

Drive-BRT

WalkExpress

Walk-LRT

DriveExpress

Drive-LRT

WalkCommuter Rail

Institute of Traffic Engineers Luncheon April 1, 2010

DriveCommuter Rail


Treatment of Space: TAZs and MGRAs

•About 10 MGRAs to 1 TAZ •32k MGRAs Tot. •All origins and destinations located at MGRA level •Highway assignments still use TAZs

Institute of Traffic Engineers Luncheon April 1, 2010


Transit Network, Stops and Access Points

•About 2,500 transit access points (stops) • Stop-to-stop skims (TransCAD) •All transit boardings/alights located at TAPs

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Transit Paths

• On-the-fly pathbuilding from origin MGRA, to boarding TAP, to alighting TAP, to destination MGRA

Institute of Traffic Engineers Luncheon April 1, 2010


Tour Destination, Time-of-Day, Mode, Stop Location 1.

Select Primary Destination

2. Select Departure/Arrival Period

3. Select Primary Mode

4. Select Stop Location Institute of Traffic Engineers Luncheon April 1, 2010


Time-Use Concept

Recalculate residual time windows

5-6

1-Work

18-19

7-17

5

2-Discret 20-23

23

Institute of Traffic Engineers Luncheon April 1, 2010


Tour-Based Model Output Household Data, Person Data, Tour/Trip List HID 1 1 1 1

PID 1 1 2 3

TID 1 2 1 1

PUR 2 1 4 2

MOD 1 2 1 4

SB 0 1 0 1

SA 1 0 0 1

OTAZ 943 943 943 943

DTAZ 987 731 952 565

S1TAZ 0 856 0 698

S2TAZ 964 0 0 982

TLOR 1 3 1 1

TLDS 3 3 2 2

Work Trip Frequency Distribution: Auto Ownership 1, Income Group 1-2 Estimated vs. Observed 6.0%

5.0%

Trip Tables

Frequency

4.0% Observed Estimated 3.0%

2.0%

1.0%

ÂŻ

Peak Highway Travel Time (minutes)

Maps, Graphics

Assignment Institute of Traffic Engineers Luncheon April 1, 2010

Other Summaries

59

56

53

50

47

44

41

38

35

32

29

26

23

20

17

14

8

11

5

0.0%


What Sort of Measures/Visuals are Now Possible? • ABM results in a complete activity diary for all SANDAG residents – A wealth of activity/travel results – Just about any custom report/query/visual is now possible

• Scenario Testing – – – – – –

Capacity improvements HOV, HOT lane scenarios Cordon Pricing Land-use policies New Starts Equity Analysis

• Example Outputs Institute of Traffic Engineers Luncheon April 1, 2010


Tracing of Activities/Tours

Institute of Traffic Engineers Luncheon April 1, 2010


Mode Share by Person Type

Institute of Traffic Engineers Luncheon April 1, 2010


90

75

Travelers By Age

60

45

30

15

0

Institute of Traffic Engineers Luncheon April 1, 2010


Persons Not At Home By TAZ and Hour

Institute of Traffic Engineers Luncheon April 1, 2010


Persons By TAZ and Hour (Daytime Population)

Institute of Traffic Engineers Luncheon April 1, 2010


Mean Delay Peak Period Travel

Institute of Traffic Engineers Luncheon April 1, 2010


Time Spent Traveling by Income & Person Type

Institute of Traffic Engineers Luncheon April 1, 2010


1. Population Synthesis 2. Long-term

3. Mobility

4. Daily Mandatory

2.1. Usual workplace / school

3.2a. Car ownership

4.1. Person pattern type

Nonmandatory

Home

Year 1 (2009): Individual Mandatory Tours

Individual NonMandatory Tours

4.2.1. Frequency

4.5.1a. Frequency & Purpose

At-work sub-tours 4.6.1a. Frequency

5. Tour level

5.2a. Stop frequency & Purpose

Daily Trip Productions By Purpose

6. Trip level (4-Step Models)

Trip Distribution Mode Choice Trip Assignment

Institute of Traffic Engineers Luncheon April 1, 2010

Simplified activity-based travel generation models estimated, implemented, and calibrated


Model Development Schedule • Year 2 (2010) – On-board survey data available – Tour mode choice, time-of-day choice, destination choice

• Year 3 (2011) – Trip-level models estimated, implemented – Toll transponder ownership – Employer-provided parking and parking lot choice

• Year 4 (2012) – Special market models (visitors, air passengers, special events) – PECAS (land-use model) integration – Model validation Institute of Traffic Engineers Luncheon April 1, 2010


Questions and Discussion

Joel Freedman freedman@pbworld.com 503.478.2344 Institute of Traffic Engineers Luncheon April 1, 2010

2010.04.SANDAG_ABM_Joel Freedman  

The SANDAG Activity The SANDAG Activity- - Based Based Travel Travel Model Model Institute of Traffic Engineers Luncheon Presentation April...

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