City of Lee’s Summit Department: Public Works Department Memorandum To: From: Date: Re:
Michael Park, PE, PTOE, City Traffic Engineer Shannon Jeffries, PE, PTOE, Senior Staff Engineer May 22, 2013 Second Street Corridor Study
Background This study of the Second Street Corridor analyzes Second Street from Jefferson Street to Independence Avenue. The primary focus of this study is to determine if any safety or efficiency concerns exist within the corridor and to make recommendations accordingly. In addition, the study will consider a “complete streets” or “livable streets” philosophy osophy that accommodates various modes of transportation. The study includes an analysis of the transportation needs of the corridor as well as a comparison of the existing conditions and proposed recommendations. Data such as crash history, level of service se (LOS), vehicle queues, s, travel delay, walking routes and traffic volumes were utilized to identify requirements of the corridor. The analysis will compare and contrast these parameters to measure effect of recommended improvements.
Existing Conditions Roadway Characteristics Second Street provides access to the Gamber Community Center, LLee’s Summit Elementary School, Lee’s L Summit United Methodist Church, downtown LLee’s Summit businesses, City Hall and several surrounding neighborhoods. The roadway is classified as a minor arterial with average daily traffic (ADT) volumes ranging from 9,000 to 11,000 vehicles along the corridor from Jefferson Street to Independence Avenue. Based on historical count data, the ADT along this segment of Second Street has remained fairly level over the past few years. Second Street between Jefferson Street and Eastridge Street is striped as a four four-lane lane section with a width of 40 feet from edge-of-pavement pavement to edge edge-of-pavement pavement (EOP). However, the width of Second Street increases to 42 feet between Eastridge and Independence Avenue. Second Street is an undivided roadway with curb and gutter, storm inlets and sidewalk infrastructure throughout much of the corridor. The speed limit along Second Street is 30 mph west of Grand Street and 35 mph east of Grand Street. A school zone with a 20 mph speed limit exists between Douglas Stree Streett and Johnson Street during specific weekday times during the school calendar year, as indicated by flashing beacons. Crosswalks for at least one crossing are provided at all of the signalized intersections. Second Street is a designated bicycle route on the City’s Greenway Master Plan and proposed Bicycle Transportation Plan. The corridor has no continuous street lighting, but lighting is provided at some intersections. Exhibit A in the technical appendix illustrates the existing conditions on the Second Street corridor.
Intersection Analysis There are four intersections that were studied that are currently signalized. The signalized intersections are comprised of the following: • • • •
Second Street and Market Street Second Street and East Main Street Second Street and Douglas Street Second Street and Independence Avenue
All four of the traffic signals were analyzed to determine the existing level of service (LOS), vehicle queuing, and intersection delay utilizing a static model, Synchro 7.0, and a dynamic model, SimTraffic 7.0, which are widely accepted traffic operational analysis software in the traffic engineering industry. Level of service is defined by the Highway Capacity Manual (HCM), published by the US Transportation Research Board, to measure transportation operation as a function of the average vehicle control delay. The LOS system uses the letters A through F, with A being the best condition and F being the worst condition. The City of Lee’s Summit has adopted by Council resolution a level of service goal of C for traffic signal and stop controlled intersections, but also recognizes in certain circumstances a LOS D, E or F may be acceptable. Exhibit’s B and C in the technical appendix display the existing AM and PM peak hour LOS and vehicle queuing results for each movement. For this study, as determined by daily traffic counts, the AM peak hour is defined as 7:15 – 8:15 AM and the PM peak hour is defined as 4:45 – 5:45 PM. The traffic signals at Market Street and Independence Avenue are built with overhead mast arms and signal heads over each lane. However, the traffic signals located at East Main Street and Douglas Street are comprised of pedestal heads on the four corners of each intersection. Pedestrian push button activation and pedestrian signal indications are provided at the intersections of Second Street with Market Street and Independence Avenue. Improvements to the Second Street and Douglas Street signal have been planned and funded to occur within the next twelve months. These improvements will provide mast arms, overhead signal heads, pedestrian push button activation and pedestrian signal indications. In addition to the signalized intersections there are four two-way stop controlled intersections that were analyzed. The studied unsignalized intersections are comprised of the following: • • • •
Second Street and Jefferson Street Second Street and Green Street Second Street and Eastridge Street Second Street and Grand Street
Tables 1 and 1A summarize the results of the existing intersection LOS and average vehicle delay during the AM and PM peak hours for signalized and unsignalized intersections. Supporting data can be found in the technical appendix.
Table 1 - Existing Corridor Intersection Analysis LOS Signalized Intersections AM PM Second Street and Market Street A B Second Street and East Main Street A A Second Street and Douglas Street B B Second Street and Independence Avenue B B
Delay (sec) AM PM 7.1 10.4 4.8 8.7 10.3 12.4 13.3 17.4
Table 1A â€“ Existing Corridor Intersection Analysis Unsignalized Intersections Second Street and Jefferson Street Second Street and Green Street Second Street and Eastridge Street Second Street and Grand Street
LOS AM PM A A A A A A A A
Delay (sec) AM PM 5.3 6.2 1.9 2.4 0.3 0.3 1.5 2.1
Crash Data Crash reports for the past five years within the study area were reviewed to help identify any crash patterns. The data showed that the predominant crash type throughout the corridor was angle crashes. It is believed that this high frequency of angle crashes is caused by the limited sight visibility of the vehicles in the inside lane of oncoming traffic while making left turns at an intersection. The existing four-lane section on Second Street forces left-turn traffic to cross two lanes of oncoming traffic with potentially limited sight distance and therefore increases the likelihood of a crash. The second predominate crash type is rear-end. Rear-end crashes were often found to result from the frequent stops incurred by the inside lanes due to yielding left-turn traffic. Right-turn traffic in the outside lanes also contributed to rear-end collisions. There did not appear to be any definitive data that linked crashes to a particular time of day or night. Table 2 summarizes the crash history of the corridor for the last five years. Individual crash diagrams for the corridor have been generated and can be found in the technical appendix.
Table 2 - 2nd Street Corridor Crash Summary Location Crash Severity Crash Type Frequency Right-Angle 4 Rear-end 9 PDO Sideswipe 1 2nd & Jefferson Fixed Object 1 Fixed Object 1 Injury Right-Angle 1 Sideswipe Midblock b/w Jefferson & 1 PDO Fixed Object Market 2 Right-Angle 12 Rear-end 3 PDO Sideswipe 2 2nd & Market Fixed Object 1 Right-Angle 2 Injury Rear-end 2 Midblock b/w Market & PDO Sideswipe 1 Main Right-Angle 8 PDO Rear-end 7 2nd & Main Sideswipe 1 Right-Angle 1 Injury Rear-end 3 Right-Angle 22 Rear-end 16 PDO Sideswipe 4 2nd & Douglas Fixed Object 3 Right-Angle 5 Injury Rear-end 1 Sideswipe 1 Midblock b/w Douglas & PDO Rear-end 1 Green Right-Angle 9 Head On 1 2nd & Green PDO Backed Into 1 Sideswipe 1 Right-Angle 1 Rear-end 1 2nd & Johnson PDO Sideswipe 1 Fixed Object 1
Table 2, continued - 2nd Street Corridor Crash Summary Midblock b/w Johnson & PDO 1 Sideswipe Eastridge Midblock b/w Eastridge PDO 1 Right-Angle and Grand Right-Angle 5 PDO Rear-end 2 2nd & Grand Sideswipe 2 Right-Angle 2 Injury Rear-end 1 Sideswipe 1 Midblock b/w Grand & Fixed Object 3 PDO Corder Right-Angle 2 Rear-end 3 Fixed Object 1 Midblock b/w Corder & PDO Sideswipe 1 Independence Rear-end 1 Right-Angle 5 Rear-end 2 PDO Backed Into 1 2nd & Independence Fixed Object 1 Sideswipe 1 Injury Right-Angle 1 Midblock b/w PDO Rear-end 1 Independence & 291 Grand Total
The following five intersections were identified as having the highest crash frequency: • • • • •
Second Street and Douglas Street Second Street and Market Street Second Street and Main Street Second Street and Jefferson Street Second Street and Grand Avenue
Sight Distance Staff collected sight distance data at intersections along the corridor. Sight distance is a road design principle which helps ensure that a vehicle traveling at the speed limit will be able to stop before reaching an object in its path. Adequate sight distance is a way of allowing drivers enough unobstructed vision in order to avoid a collision. Required sight distance at an intersection is based on vehicle speed and is documented in the American Association of State Highway and Transportation Officials (AASHTO) A Policy on Geometric Design of Highways and Streets. Intersection sight distance was determined to be inadequate at the following intersections. Measured sight distance, recommended sight distance and stopping sight distance are detailed for each location in Table 3.
Location SW Second Street at SW Market Street SW Second Street at the alley between SW Market Street and SW Main Street SW Second Street at the alley between SW Market Street and SW Main Street SE Second Street at SE Main Street SE Second Street at SE Main Street SE Second Street at SE Eastridge Street SE Second Street at SE Eastridge Street SE Second Street at SE Grand Avenue
Table 3 - Intersection Sight Distance Measured Speed Direction Sight Approach Limit Looking Distance (mph) (feet)
Recommended Sight Distance (feet)
Stopping Sight Distance (feet)
The following recommendations address sight distance concerns for each intersection listed in Table 3. •
Right-turns on red are currently prohibited at the signalized intersection of Second Street and Market Street for the southbound direction. The vertical curvature of the street restricts sight distance to be less than the stopping sight distance for 30 mph. Right-turns on red should continue to be prohibited. Retaining walls at the alley between Market Street and Main Street severely restrict sight distance to be less than the stopping sight distance for a speed of 30 mph. Southbound traffic on the alley should be prohibited to enter at Second Street to eliminate conflicts with southbound traffic at the intersection. Alternate routes are available for southbound traffic. Measured sight distance at Second Street and Main Street for the northbound direction looking to the west is slightly less than the recommended sight distance. This is a signalized intersection, thus right-of-way for movements at the intersection are designated by the signal. No crashes have been recorded within the past five years which indicated inadequate sight distance for the northbound approach as a cause. Additionally, a signal ahead warning sign for eastbound traffic implies that side street traffic may be present.
Right-turns on red are currently prohibited at the intersection of Second Street and Main Street for the southbound direction. A large retaining wall severely restricts sight distance to be less than the stopping sight distance for 30 mph. Right-turns on red should continue to be prohibited. The measured sight distance at the intersection of Second Street and Eastridge Drive for the northbound direction is less than the recommended sight distance. Due to a building in the southwest corner of the intersection sight distance is severely restricted for northbound traffic looking west. Northbound traffic between Grand Avenue and Second Street should be prohibited to eliminate conflicts with northbound traffic at the intersection. Grand Avenue is approximately 130 feet east of Eastridge Drive and could serve as an alternate route for northbound traffic. Measured sight distance at the intersection of Second Street and Grand Avenue is less than the recommended sight distance for northbound traffic looking west. A cross road warning sign is provided approaching this intersection.
Potential Conditions Given the existing conditions, staff considered several improvements within the corridor. The following recommendations address the safety concerns of the corridor and the goal of creating a “complete street” or “livable street” for various modes of transportation. Road Diet Presently, the Second Street corridor carries approximately 9,000 to 11,000 vehicles per day on a fourlane thoroughfare. Based on historical count data, the ADT along this segment of Second Street has remained fairly level over the past few years. Traffic projections on Second Street are 12,000 to 14,000 vehicles per day for a 20-year horizon, based on future growth that accounts for development, redevelopment and growth in the area. It is recommended that the corridor undergo a “road diet” to increase safety where capacity is underutilized. A road diet is a common national practice in which the number of lanes along a corridor is reduced or the widths of travel lanes are narrowed. For this study the four-lane Second Street corridor was considered for reduction to a three-lane roadway (one lane each way and center turn lane) through the use of pavement striping. Road diets have proven to be effective on roadways with an ADT less than 20,000, depending on the environment, traffic patterns and access management. A corridor like Second Street should accommodate a daily traffic volume in excess of current and projected future demand with a three-lane section. The City most recently applied “road diet” principles to Jefferson Street between US-50 Highway and Second Street in 2011. Blackwell Road was changed from a 4-lane to a 3-lane section through a “road diet” in 2007. While Second Street is unique, there are several examples of similar volume roads in Lee’s Summit with three lanes: • • • •
3rd Street, between Blue Parkway and Jefferson Street (ADT = 10,500) Independence Avenue, between Tudor Road to Colbern Road (ADT = 7,000) Scruggs Road, between Todd George Parkway and Blackwell Parkway (ADT = 5,400) Longview Road, between Sampson Road to Ward Road (ADT = 4,300)
One feature of a road diet is the potential to decrease angle collisions that occur at intersections. As a three-lane facility, the left-turn lanes on Second Street would be aligned at each intersection, increasing visibility of oncoming traffic and separating slower left-turning movements from the higher volume/higher speed through traffic. Also, the left-turning traffic is only forced to cross one lane of traffic instead of two, as required by a four-lane facility, thereby reducing vehicle conflict points within the intersection.
Another feature of a three-lane facility is increased pedestrian safety. Pedestrians can focus on crossing one lane at a time instead of two lanes, if necessary. Children, older adults and the disabled can utilize the two-way left turn lane as a pedestrian refuge area to stage road crossing during periods where gaps in traffic may be less than comfortable. While the center turn lane is an active lane, it will likely have lower traffic volumes and speeds than that of the through lanes which better allows pedestrians to focus on crossing one lane at a time. In addition to pedestrian safety, a “road diet” will result in wider curb lanes which are more accommodating for bicycle traffic. The road diet will require a westbound lane drop and eastbound lane addition just west of Independence Avenue. It will be necessary to remove the existing four-lane striping throughout the corridor. The most cost effective and clean way to re-stripe Second Street is to coincide with a street overlay project. This will provide a smooth surface and clear delineation of the new three-lane section. This would also eliminate the need to grind off existing markings, a process that may result in misleading lane designations. Several signing modifications would also be required, including installation of regulatory two-way left turn lane signs. Table 4 summarizes the results of the corridors unsignalized intersection LOS and delay as a result of the “road diet”. The results of the signalized intersections are discussed in the Traffic Signals section of this report. Table 4 - Proposed Intersection Analysis LOS Unsignalized Intersections AM PM A A Second Street and Jefferson Street A A Second Street and Green Street A A Second Street and Eastridge Street A A Second Street and Grand Street
Delay (sec) AM PM 5.3 6.1 1.9 2.7 0.4 0.3 1.5 2.2
Signalized Intersection Control Warrant The signalized intersection control warrant was reviewed for the intersection of Second Street and Green Street. Count data was collected for all approaches at the intersection of Second Street and Green Street between April 11th and April 16th, 2012. For the purpose of reviewing intersection control, data collected during a typically weekday, Wednesday, April 11th and Thursday, April 12th, was used for analysis. Data was averaged for the two typical weekdays and used to evaluate the intersection control warrants. Review of the warrant analysis worksheets was conducted. Analysis sheets are included in the Appendix. The intersection of Second Street and Green Street does not currently meet warrants for a 4-way stop or a signal based on a 4-lane and a 3-lane section. It is recommended that the intersection continue to be controlled as a two-way ‘STOP’ controlled intersection with the ‘STOP’ controlled movement being the northbound and southbound approaches. Sidewalks and Curb Ramps Sidewalks are established intermittently throughout the corridor on one or both sides of Second Street. A walking route for the Lee’s Summit Elementary schoolchildren has been identified along the Second Street sidewalk near the school. Currently, no sidewalk exists on the south side of Second Street
between Green Street and Independence Avenue. Staff recomme recommends nds that these missing segments of sidewalk be installed to provide continuous sidewalk connections throughout the corridor. A capital improvement project to construct this section of sidewalk, including sidewalk ramp improvements, has been programmed in the he Capital Improvement Plan for fiscal year 2010.
No Sidewalk on the south side of Second Street from Green Street to Independence Avenue Another location for sidewalk improvements resides on the northeast corner of East Main Street and Second Street. The current configuration contains a retaining wall requiring sidewalk users to traverse a staircase in order to get to street level. Due to the walls close proximity to the roadway, a sight distance issue is created for southbound Main Street traffic. Als Also, o, the staircase is a potential slip hazard and is inaccessible for disabled pedestrians. It is recommended that the retaining wall be relocated to a position in which the sidewalk can run adjacent to the street, or offset from the street at street level and a ADA curb ramps be installed. These improvements carry significant costs and have not yet been programmed. Exhibit D in the technical appendix shows the conceptual improvements at East Main Street.
Retaining wall at Second Street and East Main Street
Intersection Analysis Modifying the existing lane configuration along the corridor will require improvements to the existing traffic signals. The existing traffic signals at Douglas Street and East Main Street reside on pedestal poles. In order to properly protect the Second Street left-turning traffic, it is recommended that protected plus permissive left turn phasing be installed on the traffic signals. This would require the installation of new bases, mast arms, and signal heads at the intersections. The addition of mast arms across the intersection allows for the signal heads to be aligned with the travel lanes and provides better visibility of the signal indication. Each intersection shall be equipped with pedestrian push button detectors and pedestrian signal heads. Table 5 displays the peak hour LOS and delay for each signalized intersection with the proposed 3-lane section and traffic signal improvements. Table 5 - Proposed Intersection Analysis LOS Signalized Intersections AM PM Second Street and Market Street B B Second Street and East Main Street A A Second Street and Douglas Street A B Second Street and Independence Avenue B B
Delay (sec) AM PM 11.4 14.8 9.0 8.3 9.5 13.1 13.3 17.4
Exhibit’s E and F in the technical appendix show the AM and PM proposed conditions for both the signalized and unsignalized intersections. Finally, an alternative consideration for long term improvements at the intersection of Second Street and East Main Street is to eliminate the traffic signal and convert it into a two-way stop controlled intersection. Traffic signal warrants were analyzed at the intersection for existing conditions and the possible three-lane configuration in accordance with the Manual on Uniform Traffic Control Devices (MUTCD). The warrant criteria indicate that a traffic signal is not necessary, if not for limiting sight conditions. It is believed that the traffic signal was installed as a result of the limited sight distance created by the bridge piers and the retaining wall. Curb extensions (reconstruction) and retaining wall relocation would allow for better sight lines around the bridge piers to the west and around the retaining wall to the east. Table 6 shows the LOS and delay for Second Street and East Main Street as an unsignalized, two-way stop intersection. Table 6 - Second Street and East Main Street – Two-way Stop Analysis LOS Delay (sec) Unsignalized Intersection AM PM AM PM A A 1.3 1.2 Existing Four-Lane Configuration Proposed “Road Diet” Three-Lane B B 3.0 3.7 Configuration The analysis of an unsignalized intersection at Second Street and East Main Street shows that it could be feasible to change the intersection into a two-way ‘STOP’ controlled intersection pending the sight distance issues are alleviated. Although the level of service would be acceptable during peak hour typical conditions, additional delay would be expected during events and for short periods when traffic
is detoured from Third Street by rail activity. Exhibit G in the technical appendix displays the long term recommendations for the intersection of Second Street and East Main Street. To supplement the Synchro 7.0 static model, a dynamic model was built using SimTraffic 7.0 to simulate the traffic conditions for the existing and proposed environment. The SimTraffic data and simulation confirmed that the Synchro model provided a fairly accurate portrayal of the Second Street corridor based on actual field measurements (delay and vehicle queues). The AM and PM peak hour existing and proposed vehicle queuing output is summarized in Exhibits H, I, J, and K. The vehicle queues are shown by movement and represent a close approximation of the static model within one or two car lengths. Geometric Improvements There are three intersections that should be considered for geometric improvements. The first intersection is at Second Street and Jefferson Street. The current configuration of this intersection allows for a free flow northbound right-turn movement which is controlled by a stop sign as a result of inconsistent driver behavior. This is a non-typical, urban intersection configuration and creates confusion amongst drivers. Staff recommends that the channelizing island be removed and the curbs be extended to provide a typical T-intersection configuration. The sidewalk will need to be corrected to accommodate the new intersection layout. Exhibit L in the technical appendix shows a conceptual design of the recommended improvements at Second Street and Jefferson Street. These improvements have been planned and funded in the Capital Improvement Plan for fiscal year 2012. Next, the intersection of Second Street and Eastridge Street currently has sight distances that are significantly less than what is recommended for the northbound approach. Staff recommends the addition of curb so that access to Eastridge Street is closed between Second Street and Grand Avenue. Grand Avenue, which is located 130 feet east of Eastridge Street, provides an appropriate alternate route. Exhibit M in the technical appendix displays the proposed Eastridge Street closure.
Northbound Eastridge Street between Second Street and Grand Avenue. Finally, as a long-term geometric improvement for the corridor, a roundabout for the intersection of Second Street and Independence Avenue was considered. A one-lane roundabout would provide the intersection with appropriate control and traffic calming. The roundabout would accommodate pedestrians and reduce crash frequency and severity. Exhibit N in the technical appendix shows a
conceptual layout of the roundabout within the intersection. This improvement is optional and therefore has not been pursued. Street Lighting The existing street lighting along Second Street provides low and inconsistent lighting levels for corridor users. One strategy to increase safety along the roadway during nighttime conditions is to install continuous street lighting. Street lighting along the Second Street corridor was approved by voters in the November 2007 bond election. It is recommended that a continuous street lighting system be installed to supplement the previous recommendations.
Conclusion Summary of Recommendations and Benefits Based on staff’s analysis of the Second Street corridor, there are several recommendations that will help increase the overall safety and efficiency of the thoroughfare. • • • • • • •
“Road Diet” – Reducing the corridor from four-lanes to three-lanes provides a potential decrease in crashes and increase in safety for drivers, pedestrians, and cyclists. Sidewalks and Curb Ramps – Providing these amenities will allow for pedestrians and disabled individuals to traverse the entire corridor continuously and safely. Traffic Signal Improvements – Updating the traffic signal infrastructure with mast arms, protected left turn phasing and pedestrian actuation will provide better signal visibility and safety for approaching traffic, and better pedestrian accommodations. Monitor and improve traffic signal timings/coordination throughout the corridor. Second Street and Jefferson Street Improvements – Eliminating the channelizing island and extending the curb lines to create a typical urban T-intersection will help to reduce driver confusion and crashes. Second Street and Eastridge Street Improvements – Closing the northbound approach to Eastridge Street will eliminate the sight distance issue and the potential for crashes. Second Street and Main Street Improvements – By extending the northbound approach curb and offsetting the retaining wall for the southbound approach, drivers will have enough sight distance for the intersection to become a two-way stop. In addition, the newly aligned sidewalk will provide ADA compliant accessibility to disabled individuals. Street Lighting – A continuous street lighting system will provide better visibility for drivers, pedestrians and cyclists during nighttime conditions.
Exhibit O in the technical appendix displays the recommended improvements throughout the corridor.
• Exhibits • Intersection Crash Diagrams • Intersection Analysis Worksheets
Intersection Crash Diagrams
Intersection Analysis Worksheets
2nd St Improvements Corridor Study