1 Date: 4/11/2022
Subject: Bell Street and Cooley Avenue Multi-Way Stop Sign Warrant Analysis To Whom It May Concern:
The City of East Palo Alto’s Engineering Division performed a multi-way stop sign analysis for the Bell Street and Cooley Avenue intersection. The attached report discusses the full analysis and based on the report, staff recommends a multi-way (three-way) stop sign at this time.
The analysis was completed in response to a resident’s request to verify if a multi-way stop sign installation is warranted. The residents written request may be found in Appendix E. The guidelines outlined in the California Manual of Uniform Traffic Control Devices (California MUTCD) were used for the analysis. Currently there are two three-way intersection that are stop controlled on Bell Street. In overall consideration of existing conditions, a multi-way stop sign is recommended.
Please let me know if you have additional questions about the analysis or the recommendations.
Sincerely,
Batool Zaro
Assistant Civil Engineer
[email protected]
City of East Palo Alto
Attach: Multi-Way Stop Control Warrant Analysis Report
CITY OF EAST PALO ALTO
PUBLIC WORKS DEPARTMENT
ENGINEERING DIVISION
1960 Tate Street, East Palo Alto, CA 94303 (650) 853-3189 2 MULTI-WAY STOP CONTROL WARRANT ANALYSIS REPORT
BELL STREET AND COOLEY AVENUE
IN THE CITY OF EAST PALO ALTO
INTRODUCTION
There was a safety concern brought up regarding the visibility issues at the Bell Street and Cooley Avenue intersection and a multi-way (three-way) stop sign has been requested. This analysis is to verify if a three-way stop sign installation is warranted and recommended based on standard guidelines.
Current conditions consist of two three-way intersections. Cooley Avenue runs in the north/south direction and Bell Street runs in the east/west direction. The east and west legs of Bell Street will be analyzed separately as two different intersections. The location is demonstrated in Image 1 below. Bell Street is stop controlled and Cooley Avenue is uncontrolled. The intersection is within the City of East Palo Alto’s jurisdiction.
Image 1: Location Map, City of East Palo Alto
N
3 BACKGROUND
Bell Street and Cooley Avenue are neighborhood streets. Cooley Avenue is the “major” street in this intersection and is considered a connector- neighborhood street because it typically serves more destinations and helps distribute local traffic to neighborhood streets. The speed limit on all streets is 25 mph. At the intersection Cooley Avenue is approximately 38 feet wide, and the 2-lane roadway is separated by centerline striping. Parking is permitted on both sides of the street. The north and south direction side consist of curb, sidewalk, and gutter.
See Image 2 and Image 3 for photo images of Cooley Avenue.
Image 2: Cooley Avenue Looking North Image 3: Cooley Avenue Looking South Bell Street (the eastern direction of the intersection) is a neighborhood street that’s approximately 36 feet wide, and the 2-lane roadway provides one lane in each direction that is separated by centerline striping with parking allowed on both sides of the street. The roadway has curb, gutter, parkway, and sidewalk.
There is a STOP sign, a white ‘STOP’ pavement marking, and a white limit line at the intersection.
See Image 4 for a photo image of the Bell Street east leg. 4 Image 4: Cooley Street Facing Bell Street (east leg)
Bell Street (the western direction of the intersection) is a neighborhood street that’s approximately 40 feet wide, and the 2-lane roadway provides one lane in each direction that is separated by centerline striping with parking allowed on both sides of the street. The roadway has curb, gutter, parkway, and sidewalk.
There is a STOP sign, a white ‘STOP’ pavement marking, and a white limit line at the intersection.
See Image 5 for a photo image of the Bell Street west leg.
Image 5: Cooley Street Facing Bell Street (west leg)
5 WARRANT GUIDELINES
The City of East Palo Alto follows State guidelines outlined in the California Manual on Uniform Traffic Control Devices (MUTCD) when determining if traffic control devices should be installed. The guidelines outlined in the California MUTCD were used for this analysis. The manual outlines minimum guidelines regarding traffic volumes, collisions, speed, visibility, and other criteria in order to warrant traffic control devices like the installation of a multi-way (3-way) stop sign in this case.
The California MUTCD application guideline criteria for a multi-way stop is described below:
1. As an interim measure where traffic control signals are justified. “Where the traffic control signals are justified, the multi-way STOP is an interim measure that can be installed quickly to control traffic while arrangements are being made for the installation the traffic control signal”.
2. Reported crashes – five or more in a 12-month period that are susceptible to correction by a multiway stop installation.
3. Minimum traffic and pedestrian volumes, speeds, and delay as outlined in Section 2B.07.
4. Where a combination of the above criteria are all satisfied to 80 percent.
When any one, or a combination of these criteria is met, then a multi-way stop application should be considered. A multi-way stop sign is usually not recommended when the criteria are not met. The California MUTCD guidelines described above are included in Appendix A.
MULTI-WAY STOP ANALYSIS
The California MUTCD outlines the guidelines describing the minimum collisions and traffic volumes necessary to warrant a multi-way stop sign. Engineering judgment must also be considered along with these guidelines. One important thing to note is that a stop sign will not stop the speeding issue; however, it might help guide vehicles to safely make their turns. Additional guidance criteria found in the manual include the following important statements: “YIELD or STOP signs should not be used for speed control… In most cases, the street carrying the lowest volume of traffic should be controlled…” Collision History
The guidelines in the California MUTCD outline that a minimum of (5) reported crashes occurring in a 12-month period that are susceptible to correction by a multi-way stop installation must occur in order to satisfy this warrant. The crashes include right-turn and left-turn collisions, as well as right-angle collisions and pedestrian-vehicle collisions.
The collision history was gathered by the City’s Engineering Division from the City of East Palo Alto’s Police Department (PD). A comprehensive 3-year traffic collision history summary report was prepared for this intersection and reviewed for collisions susceptible to correction by the installation of a multi-way stop. Table 1 demonstrates a 3-year summary of collisions at this intersection. 6 TABLE 1
3-YEAR ACCIDENT HISTORY
PD COLLISION HISTORY SUMARY
2018 2019 2020
Intersection Date Type of
Collision
Date Type of Collision Date Type of Collision
Bell Street
and Cooley
Avenue
6/9/2018 rear end 2/11/2019 broadside 04/21/2020 broadside 3/12/2019 side swipe
6/30/2019 head on
9/01/2019 broadside
11/02/2019 side swipe
Notes: Information above is derived per the 3-year intersection traffic collision database report gathered from the East Palo Alto’s Police Department (PD).
As shown in Table 1 above, there have been seven (7) reported collisions at or near this intersection over the three (3) year timeframe. Since the collision warrant requires a minimum of five (5) reported crashes susceptible to correction by a multi-way stop, to occur within a 12-month period, the collision warrant is satisfied. It is important to note that since most of the police reports do not specify whether the accident occurred at the eastern/western leg, it is assumed to be the number of accidents for both. No accidents occurred at this intersection in 2021 or January-March of 2022. The EPA PD collision report is included in Appendix B.
Traffic Volumes
The City of East Palo Alto collected Average Daily Traffic (ADT) vehicular approach counts using a platform called Streetlight Data. The results are demonstrated in Table 2. The traffic volume data collected for this intersection is included in Appendix C 7 TABLE 2
VEHICLE COUNTS
COOLEY AVENUE & BELL STREET
EAST LEG
WEST LEG
8 Cooley Avenue is considered the “major” street at this three-way intersection. Bell Street is considered “minor” streets since drivers are required to stop at Cooley Avenue and look both ways before making a left or right turn. It is anticipated that the minor streets receive less traffic volume than the major street.
A part of the California MUTCD guideline criteria calls for a reduction in the required minimum volumes when the critical approach speed (or 85th-percentile speed) on the major street exceeds 40 MPH. If this is the case, the minimum vehicular volumes to be met for a multiway stop sign installation are reduced to 70%. As mentioned, the speed limits on all streets are 25 MPH. Using the Streetlight Data platform, it was confirmed that the 85th-percentile speed is not greater than the 40 MPH limit required to reduce traffic volumes.
Table 3 below shows the California MUTCD minimum traffic volume criteria for a multi-way stop sign with the highest 8-hour traffic counts data for this intersection. Both Part 1 and Part 2 need to be satisfied in order to fulfil the traffic volume warrant.
TABLE 3
CA MUTCD MULTI-WAY STOP CRITERIA
Part 1:
The vehicular volume
entering the
intersection from the
major street approaches
(total of both
approaches) averages at
least 300 vehicles per
hour for any (8) hours
of an average day
East/West Leg
Results: Satisfied
Total average vehicles
= approximately 705
vehicles
and Part 2:
The combined vehicular,
pedestrian, and bicycle volume
entering the intersection from the
minor street approaches (total of
both approaches) averages at least
200 units per hour for the same (8)
hours, with an average delay to
minor-street vehicular traffic of at
least 30 seconds per vehicle during
the highest hour.
East Leg Results:
Not Satisfied
= 53
(311 vehicles +94 pedestrians +19
bicyclists)/8 hours
West Leg Results:
Satisfied
= 230
(1,437 vehicles+306 pedestrians
+94 bicyclists)/8 hours
but Part 3:
If the 85th -percentile
approach speed of the
major street traffic
exceeds 65 km/h or
exceeds 40 mph, the
minimum vehicular
volume warrants are (70)
percent of the above
values.
East Leg Results:
Not Satisfied
As shown above, the average hourly intersection traffic for the highest 8-hour period did not satisfy Part 2 for the eastern leg; however, both conditions were satisfied for the western leg. Therefore, the minimum traffic volume warrant is not satisfied for the eastern leg but is satisfied for the western leg. 9 Visibility
On-site field visits were made to determine if there are restricted sight distances due to the geometry of the intersection and other potential obstructions. The driver sight distances were measured from the sidestreet approaches since they are required to stop before proceeding to makes a left or right turn onto Cooley Avenue. The minimum stopping sight distances are derived from the stopping sight guidelines in the California MUTCD (reference Appendix D). For a 25-mph street, a minimum stopping sight distance of 155 feet is required. The stopping sight distance was measured on the field from a “typical” vehicle stopped location at Bell Street looking for traffic approaching on Cooley Avenue. An orange cone was placed to mark the distances and photos were taken.
When looking north and south from Bell Street east leg the driver’s line of sight is obstructed by parked vehicles; however, a clear line of sight is available when the drivers encroach past the stop bar. Based on field observation, staff found that vehicles can safely encroach past the stop bar in order to make their turns. The images on the left demonstrate the drives visibility behind the stop bar and the image on the right demonstrate when drivers pass the stop bar. See Image 6 and 7 for the east leg of Bell Street.
When looking north from Bell Street west leg the driver’s line of sight is obstructed by parked vehicles, and vehicles must encroach further out then the eastern leg in order to get a clear line of sight. Based on field observation, staff found that when looking south it is slightly more challenging to see oncoming vehicles due to the slight angle of the intersection and due to the fact that the southern curb is not red curbed like the northern curb. The images on the left demonstrate the drives visibility behind the stop bar and the image on the right demonstrate when drivers pass the stop bar. See image 8 and 9 for the west leg of Bell Street.
Image 6: Bell Street East Leg Facing Cooley Avenue (Looking North) 10 Image 7: Bell Street East Leg Facing Cooley Avenue (Looking South) Image 8: Bell Street West Leg Facing Cooley Avenue (Looking North) 11 Image 9: Bell Street West Leg Facing Cooley Avenue (Looking South)
MULTIWAY STOP ANALYSIS SUMMARY
After reviewing the California MUTCD four main guidelines described in this report, the western leg of the intersection does meet the minimum warrant requirements.
The guidelines are: 1. As an interim measure where traffic control signals are justified; 2. Reported crashes – five or more in a 12-month period that are susceptible to correction by a multi-way stop installation; 3. Minimum traffic and pedestrian volumes, speeds, and delay as outlined in Section 2B.07;
4. Where a combination of the above criteria are all satisfied to 80 percent.
In summary, based on the collision history gathered, seven (7) accidents occurred at this intersection in the three-year period. The minimum guideline calls for at least five (5) accidents within a 12-month period. The reported accidents warrant a multi-way stop. Condition 2 is satisfied because more than (5) crashes occurred at this intersection during a 12-month period.
The average minimum hourly volumes were satisfied for the west leg of Bell Street as demonstrated in Table 3; therefore, condition (3) is satisfied.
The California MUTCD criteria is met for this location.
Although a multi-way stop sign was requested for the eastern leg, it was found that the eastern leg did not meet MUTCD warrant requirements, but the western leg did. Installing a multi-way stop sign at the western leg would help provide sufficient gaps for vehicles making turning movements from the eastern leg.
12 RECCOMENDATION
A multi-way stop sign is recommended for the three-way intersection, at the western leg, based on MUTCD warrant requirements.
MULTIWAY STOP ANALYSIS SUMMARY
After overall analysis, a multi-way (three-way) stop sign installation is not recommended at this time for Bell Street eastern leg; however, it is warranted at the western leg of the intersection. There are no other recommendations at this time.
13 APPENDIX A
MULTIWAY STOP APPLICATIONS
GUIDELINES: CALIFORNIA MUTCD
14 15
16 17
APPENDIX B
POLICE DEPARTMENT COLLISION HISTORY REPORT
CITY OF EAST PALO ALTO ALBERT PARDINI
POLICE DEPARTMENT CHIEF OF POLICE
141 Demeter Street (650) 853-3125 Phone
East Palo Alto, CA 94303 [email protected]
_________________________________________________________________ Vehicle Accidents at the intersection of Bell Street and Cooley Avenue January 1, 2018 – January 14, 2021
There was a total of seven (7) vehicle accidents at the intersection of Bell Street and Cooley Avenue from January 1, 2018 through December 31, 2020 (three years). This information is limited in that it only covers the accidents that were either reported to or discovered by the police. These numbers are not all inclusive as they do not include accidents that were not reported to the police department, reports made to the Department of Motor Vehicles, and reports made to insurance companies. It is possible that some vehicle accident reports that were made online and/or that were not reported or entered into our record keeping system as of date are also excluded. For more complete statistics please reference the Statewide Integrated Telecommunications System. 1 For further details on the accidents, please refer to the attached excel spreadsheet. 1 Statewide Integrated Telecommunications System (SWITERS) is maintained by the California Highway Patrol and information can be accessed online. http://www.chp.ca.gov Numbers are subject to change as accidents may have been reported after the date the data was pulled on 01-14-2021.
Case # Date Time Location Cause Locale
18-1885 06/09/2018 2059 BELL ST/COOLEY AV driver error street 19-0488 02/11/2019 1808 BELL ST/COOLEY AV driver error street 19-0835 03/12/2019 740 BELL ST/COOLEY AV driver error intersection 19-2170 06/30/2019 1836 2195 COOLEY AV driver error street 19-2944 09/01/2019 1204 BELL ST/COOLEY AV driver error intersection 19-3605 11/02/2019 1700 BELL ST/COOLEY AV driver error street 20-1135 04/21/2020 1236 BELL ST/COOLEY AV driver error intersection Weather Road Type Road Condition Traffic Signal Speed Limit Light Conditions Severity dark city street clear not applicable 25 street lights no injuries clear city street clear light 25 dark minor injuries
clear city street clear stop sign 25 day no injuries
clear city street clear not applicable 25 day no injuries clear city street clear stop sign 25 day minor injuries dark city street clear not applicable 25 street lights fatal injuries clear city street clear stop sign 25 day no injuries
Minor Injuries Major Injuries Fatal Injuries DUI Involved Collision Type Collision Direction Caused By Juve? 0 0 0 no vehicle - vehicle rear end no
1 0 0 no vehicle - bicycle broadside no
0 0 0 no vehicle - vehicle side swipe no
0 0 0 no vehicle - object head on no
2 0 0 no vehicle - vehicle broadside no
0 0 0 no vehicle - vehicle side swipe no
2 0 0 no vehicle - vehicle broadside no
Primary Collision
Factor
Special Conditions Hit & Run Misd. Hit & Run Felony Mile Post Occurred On At Intersection 22107 cvc NONE no no BELL ST
21650.1 cvc yes no COOLEY AV DONOHOE ST
22107 CVC yes no BELL ST COOLEY AV
22107 VC no no COOLEY AV
22450 (A) CVC no no BELL ST COOLEY AV
22107 CVC yes no BELL ST
yes no BELL ST COOLEY AV
Other Location
COOLEY
BELL ST
COOLEY AV
18 APPENDIX C
TRAFFIC VOLUMES
COUNT DATA
VEHICLE COUNTS
COOLEY AVENUE & BELL STREET
EAST LEG
WEST LEG
19 APPENDIX D
CALIFORNIA MUTCD STOPPING SIGHT GUILDELINES
20 21
APPENDIX E
MULTI-WAY STOP SIGN ANALYSIS REQUEST
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Good Morning Theodore,
Thank you for reaching out regarding your concern. In order to install a multi-way stop sign we would need to perform a multi-way stop analysis following State guidelines. Once we finish the analysis we take the item to the Public Works and Transportation Commission and then they review the analysis.
There are technically two Bell Street & Cooley Avenue intersections, so I just want to verify if you are requesting the northern or southern intersection to be reviewed? On Friday I took a look at both and visibility is a bit impaired due to parked vehicles.
Let me know if you have any additional questions.
Best,
Batool Zaro, EIT
Assistant Civil Engineer
City of East Palo Alto
Engineering Division
1960 Tate Street
East Palo Alto, CA 94303
Cell: (650) 388-8921
Email: [email protected]
From: Theodore Aronson <[email protected]>
Sent: Thursday, August 19, 2021 10:06 AM
To: Engineering <[email protected]>
Subject: Stop Sign Request: Bell St & Cooley Ave
Good Morning,
I would like to request a 3 way stop be installed at the intersection of Bell Street & Cooley Avenue in East Palo Alto, CA. Currently the intersection is rather dangerous as it is difficult to see oncoming cars due to parked cars on the street. I would be happy to talk to someone further about this and the process for requesting the stop sign installation. My phone number is . Thank you!
Sincerely,
Ted Aronson