8-12-04 Minutes.

04-B Yellow Change Intervals Timing for the Signals

Chairman Fisher [[ employee, City of LA ]] asked Committee Member Hamid Bahadori to address the agenda item of yellow change interval timing for signals.

Hamid Bahadori [[ employee, Auto Club of So. Cal ]] noted that the yellow change interval timing issue needs immediate attention and clear policy direction from the CTCDC, especially in light of the increasing number of automated red-light cameras being used to enforce red light violations at signalized intersections. Agencies are using different methodologies to determine the yellow timing. Since there is no definition for the approach speed in the Traffic Manual, or now in the California Supplement, the issue is what is the approach speed. Is it a posted speed limit or it is an 85-percentile speed? When a motorist receives a citation, the citation does not hold up in the court because approach speed has not been defined. The red light cameras are issuing tickets on a differential of one tenth of a second. People are challenging red light violations based on the lack of definition of approach speed. The law can be defended if there is a definition for the approach speed and minimum yellow timing for the left turn movements. Hamid referred to the State of Arizona DOT. They have a more detailed policy in regards to yellow timing for the through movement and for left turn movements. Hamid stated that the following two questions need to be addressed:

? Clarification on what is the approach speed.
? Should the same speed be used for all movements, if not, then does policy need to be established for the left turns approach?

The following Section of the California Vehicle Code (CVC) requires yellow timing at signalized intersections where such automated systems are used, to be established according to the Traffic Manual (now the California Supplement).

21455.7. (a) At an intersection at which there is an automated enforcement system in operation, the minimum yellow light change interval shall be established in accordance with the Traffic Manual of the Department of Transportation.

Gerry Meis [[ employee, CalTrans ]]stated that there is draft language in the agenda packet which addresses the approach speed issue. However, it does not address the left-turn movement yellow timing. This is only a draft, any suggestions and recommendations will be considered. Gerry agreed that due to red-light camera enforcement and that the CVC says the yellow interval shall be established in accordance with the Traffic Manual, this section needs improvement. He welcomed any suggestions for the improvement of the section. Gerry inquired, if a major change is recommenced to the Section, is there a need to change existing law?

Chairman Fisher stated that there is a need to clarify left-turn and right-turn yellow intervals. He also suggested flexibility so that a local agency can give more yellow time if it is needed. He added that the yellow interval should be based on the 85% percentile speed. The posted speed limit sometimes is not consistent with the 85 percentile due to political influence. If the posted speed is not consistent with the 85 percentile, then there will be a problem and more motorists may pass through the red light. It could also be a safety problem.

Hamid added that the Traffic Manual allows the use of the posted speed limit to determine the location of advance loops at signalized intersections.

Chairman Fisher invited the audience to give input.

Ahmad Rastegarpour, Caltrans Headquarters Office of ITS Development & Support, stated he believes that in determining the minimum yellow timing for a signalized intersection, appropriate judgment must be exercised. That judgment would be based upon numerous factors, including the posted speed, the 85th percentile speed (if available), the intersection geometrics, the traffic volumes, through and left turn movements, and other factors that would not be readily apparent to motorists using the intersection. To determine the yellow timing for the left-turn pocket, there is no guidance available. Therefore, a field review is needed to determine the left turns yellow timing which will be based on geometrics, left-turn pocket, the number of left turn lanes and other factors. He does not recommend a minimum yellow timing be set which would prohibit practitioners from adjustment based on field conditions.

Hamid commented that he was also not in favor of putting limitations on the flexibility for practitioners. However, since the red-light enforcement, vendors may be manipulating yellow timing to issue more red light violations. And since the approach speed is not defined, they are using their own criteria for the yellow timing. Secondly, the courts are throwing violations out because the approach speed not being defined.

Gerry Meis stated that the Department would consider all suggestions from the Committee and work with the Committee to resolve this issue. He said he was not in favor of going back to the legislature to amend the law. Marianne Milligan, City Attorney’s Office of Costa Mesa, stated that when a City adopts a document by reference such as the Caltrans Traffic Manual, the City also adopts later amendments. She commented that she does not believe that changes in the Caltrans Traffic Manual would require action by the legislature.

George Allen [[ employee, City of Garden Grove ]] commented that for years their jurisdiction used 3 seconds for the left-turn lane and 4 seconds for the through movements. Since the introduction of red-light cameras, the 85-percentile speed has been used to determine the yellow timing. The 85-percentile speed was measured between the advance loop and the limit line. The 85- percentile speed was used to determine the yellow timing for the left-turn and the through traffic. In his opinion, there should be 3.2 seconds minimum for the left turns and use the table for the through movement. George added that there is a need to define the approach speed. If all agencies are using the same definition then everyone is consistent.

There was a lengthy discussion regarding the approach speed definition and the minimum yellow timing for left turns.

Hamid cited a example where if a roadway has an approach speed of 40 mph, and an agency uses a 3 second minimum yellow timing for the left turn, then a citation will not hold up in court, because there is no separate guideline for the determination of yellow timing for the left-turns. The Traffic Manual says that the minimum yellow timing is based on the approach speed, so it applies to both through and left turn movements.

Marianne stated that local agencies could defend their case if the definition of approach speed is clear. It could be an 85 percentile or posted speed limit. Approach speed must be clarified. If the Committee suggests that the left turn must use a minimum of 3.2 seconds, then all agencies will be consistent, especially when red-light cameras are used.

Farhad Mansourian suggested that this is a discussion item and regardless of what is done here today, the Committee cannot take action. He suggested forming a subcommittee to work on this and bring draft language for the Committee’s consideration during the next meeting.

Chairman Fisher established a subcommittee chaired by Hamid Bahadori [[ employee, Auto Club of So. Cal. ]] with the members being Farhad Mansourian [[ employee, County of Marin ]] , Mark Greenwood [[ employee, City of Palm Desert ]] and Gerry Meis from the CTCDC. Two outside members, Marianne Milligan, City of Costa Mesa and George Allen, City of Garden Grove, were asked to provide input. The subcommittee was asked to develop draft language for the next CTCDC meeting.
 

Draft For Discussion Only

Section 4D.10 Yellow Change and red Clearance Intervals

Support:

The purpose of the yellow signal indication is to warn traffic approaching a traffic signal that the related green movement is ending or that a red indication will be exhibited immediately thereafter and traffic will be required to stop when the red signal is exhibited.

Standard:

The minimum yellow light change interval shall be in accordance with Table 4D-102.  The posted speed limit, or the prima facie speed limit established by the California Vehicle Code (CVC) shall be used for determination of the minimum yellow change interval for the through traffic movement.

The minimum yellow light change interval for a protected left-turn/right-turn phase shall be 3.0 seconds.

Option:

The minimum yellow light change interval time for the through movement and the protected left-turn/right-turn may be increased based on a field review or by using appropriate judgment.  That judgment may be based on numerous factors, including, but not limited to, posted speed, 85^th percentile speed, intersection geometry and traffic volumes.

Table 4D-102 Minimum Yellow Light Change Interval

11-25-05

From (highwayrobbery.net)

To Mr. Will Kempton, Director, CalTrans, (916) 654-5266 fax (916) 654-6608

Dear Director Kempton:

A year ago the California Traffic Control Devices Committee discussed, and later adopted, a policy that effectively shortened the minimum length of yellow time on traffic signals equipped with red light cameras.

That policy, later published as Traffic Operations Policy Directive 05-01 of January 26, 2005, included a recommendation by the Committee that there be a review after a year.  That year now being about up, I expect that the policy will be coming under Committee consideration again, and would like to make the following observation and request.

Per the minutes of the December 8, 2004 meeting of the Committee, there were two votes on the policy.  The first vote was 6 - 2, to adopt policy applicable to the length of yellows for straight-through movements only.  In that vote, four of the aye votes came from Committee members who in my opinion had a conflict of interest.  Two of those four were employees of cities that operate red light cameras, and another two were employed by auto clubs whose main revenue stream comes from the sales of car insurance.  Had any one of the four voted differently, the policy would not have passed, as six ayes are required for passage of a motion. 

The second vote, also during the December 8 meeting, was 7 - 0 to adopt policy applicable to the length of yellows for turning movements.  Three of the seven ayes came from members who in my opinion had a conflict of interest.  Had any two of the three voted differently, the policy would not have passed.  Adding to the appearance of impropriety, during the consideration of that policy the committee requested legal advice from an attorney who was there representing a city which operates red light cameras.   

I would suggest that when the policy comes under new review, that Committee members from cities or companies which will be directly affected financially be excluded from the discussion and the voting, and further, that the Committee obtain its legal advice from a neutral source.

Sincerely,