REQUEST FOR CREATION OF 3-WAY STOP
ON VALLEY DRIVE AT 11TH STREET

 

Recommendation:

It is recommended that the City Council uphold the Public Works commission decision to:

Summary:

Residents in the vicinity of the intersection of Valley Drive and 11th Street have expressed concern for traffic safety at this intersection. They have requested that the City install stop signs on Valley Drive and that the speed limit on Valley Drive be lowered to 25 mph to address their concerns. Please refer to Attachment 1.

This matter was heard by the Public Works Commission on June 13 and July 11, 2001.  On July 24, 2001, Council directed Staff to agendize this item for Council consideration.

Background:

A letter was received from a resident of 11th Street requesting that the City consider the installation of stop signs on Valley Drive at 11th Street to create a 3-way stop. Currently, there is a stop sign on the 11th Street approach to the intersection, but there are no stop signs on Valley Drive. Please refer to Attachment 2. The primary concerns expressed by the resident are safety, speeding, and visibility. The letter also requested that the City consider reducing the speed limit on Valley Drive from the existing 35 mph to 25 mph.

Discussion:

In response to the request for a 3-way stop, Staff monitored the intersection and conducted a technical analysis to determine if a 3-way stop is warranted according to the standard Caltrans criteria. The analysis involves an assessment of traffic volumes, accident statistics, vehicle delay, and pedestrian activity. The Caltrans guidelines suggest certain threshold values that should be used in the decision-making process in order to provide consistency throughout a community and throughout the state. The warrant criteria and the actual measured values for the intersection of Valley Drive and 11th Street are shown below.

Warrant Criteria	Threshold Value	Measured Value	Warranted
Accidents per Year	5/year	1	No
Total Traffic at Intersection	500 vehicles/hour	488	No
Minor Street Vehicle & Pedestrian Volume	200 vehicles & pedestrians/hour	63	No
Delay (during peak hour)	30 sec/veh (average)	8	No

For this intersection, the traffic criteria are below the state-recommended thresholds. The criteria state that both the total traffic entering the intersection and the minor street volumes (11th Street) should be above the thresholds to justify a three-way stop. Neither of these thresholds is exceeded for the heaviest hour observed, which was the morning peak hour on a school day. The traffic volumes for other critical hours of the day (i.e., the noon hour and the afternoon peak hour) were lower than the volumes shown in the above table. The table, therefore, reflects the time of day when traffic volumes are heaviest at this intersection.

The Caltrans guidelines indicate that the threshold values shown in the table should be exceeded for the eight busiest hours of the day. As the traffic volumes during the peak hours do not exceed the recommended thresholds, a full-day analysis is not needed. The warrant criteria for a 3-way stop installation are clearly not met because the peak hour volumes are below the thresholds.

Not only are the traffic volumes below the recommended thresholds, but the accident statistics also indicate that no more than one accident has been reported at this intersection in any single year for the past five years. The threshold criteria indicate that a 3-way stop may be warranted if there have been five accidents in any one-year period. A 3-way stop is not, therefore, justified by the accident data.

The initial conclusion of the technical analysis is that a 3-way stop is not warranted at this location. It should be noted, however, that the Caltrans criteria and thresholds are not hard-and-fast rules but are guidelines that should be used in the decision-making process. It is sometimes acceptable to install a 3-way stop if there are unique circumstances that clearly indicate that a 3-way stop would be advantageous.

At the intersection of Valley Drive and 11th Street, there are no severe visibility restrictions as the street alignment is straight and relatively flat. There are some visibility restrictions associated with development on private property; however, this situation is typical in Hermosa Beach and would not be expected to create a critical safety problem. This finding is supported by the fact that there has been no more than one reported accident at this location within a one-year period. In essence, this intersection is not unique for this area of Hermosa Beach relative to safety and visibility and does not have any special circumstances indicating that a 3-way stop would be justified.

Another issue that should be mentioned regarding the installation of stop signs at this intersection is that Valley Drive is an arterial route that is used by numerous motorists.

New stop signs would dramatically increase the air emissions, noise, fuel consumption, and risk of rear-end collisions.

As the traffic volumes, pedestrian activity, and accident statistics do not indicate that additional stop signs are warranted at this intersection and, since there are no unique conditions indicating that a 3-way stop is justified, the recommendation is to maintain status quo and not install additional stop signs at this intersection.

With regard to the request to reduce the speed limit on Valley Drive from the existing 35-mph speed limit to a new speed limit of 25 mph, the City can do this only if it can be justified by a speed survey. The speed limit on a particular street must be consistent with the findings of an engineering survey if the City intends to conduct radar enforcement of the speed limit. The speed limit must be set at or immediately below the 85th percentile of the measured traffic speeds, although a 5-mph reduction is acceptable if there is some unique circumstance. If the posted limit deviates from the findings of the survey, the location is considered to be a speed trap and radar enforcement cannot be used to issue citations. The existing 35-mph speed limit on Valley Drive is consistent with the most recent citywide survey and cannot arbitrarily be reduced.

There are, however, two basic options available for changing the speed limit on Valley Drive. One would be to conduct a new speed survey to determine if the average speeds on Valley Drive are lower than when the citywide survey was conducted. If so, then a speed limit reduction may be appropriate. The other option would be to simply replace the 35-mph speed limit signs with signs that state 25 or 30 mph. This can be done; however, the newly posted speed limit could not be enforced by using radar. This approach has been used on Gould Avenue in Hermosa Beach.

The option recommended by Staff is to conduct a new speed survey on Valley Drive to determine if a lower speed limit would be justified.

Alternatives

1. Approve Staff’s recommendation.

2. Approve the request for a 3-way stop control at Valley Drive and 11th Street and adopt the attached resolution entitled "a resolution of the city council of the city of hermosa beach, california, designating the intersection of valley drive and 11th street a three-way stop control intersection."

3. Take no action

Fiscal Impact

Funds for the installation of the required signs and markings are available under the current Operations and Maintenance budget of Street Maintenance.