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In an update to local drivers who e-mailed SDOT with complaints about signal-timing changes leading to backups at Admiral/California (previous reports Oct. 7, Oct. 9, Nov. 14 and Nov. 17), the city says it believes the problem is fixed now, and reveals it’s looking at “removing” parking on the southwest side of the intersection. We’ll follow up with the city to find out exactly which/how many spaces they’re talking about, but for now, Laura shares this e-mail she received, signed by SDOT’s Chris Faulkner:
Thank you for your recent communication to the Seattle Department of Transportation (SDOT) regarding the timing of the traffic signal light at California Avenue SW and SW Admiral Way. We received quite a few letters and emails from concerned residents, and I want to share with all of you what has been taken place at this intersection.
Initially, new timing was put into place at this intersection and several others on the corridor. This new timing took into account current traffic volumes and provided a balance that better served all users of the intersection.
We began receiving complaints almost immediately, mainly from motorists travelling eastbound on Admiral Way. I made several site visits to the location to see if I could determine where an adjustment needed to be made, but every time I was at the location, traffic was progressing well, as I had planned. After complaints continued to come in, I went to the site again, and this time I found what others had been experiencing – the signal was skipping phases and causing traffic backups.
When the new timing plan was implemented, a new controller was also installed at this intersection. Unfortunately, there was a compatibility issue between the new controller and the timing program, which caused problems to occur sporadically. When a problem is intermittent, it is almost impossible to diagnose what is not working unless you happen to be there at the time it happens. Once I was able to observe what was occurring, I was able to work towards correcting the problem.
The correction was made on November 17; I have been in the field many times since, at all times of day, to observe traffic conditions. I am now confident that everything is working as planned. The number of complaints received has slowed to a trickle, and the focus of these complaints is the weekend timing plan.
The timing favors east- and westbound movements because of the higher traffic volumes in these directions. On weekend timing, east- and westbound is still favored, but the green time is more closely split with the north- and southbound movement. This is due to increased north- and southbound volumes on weekends. If the north- and southbound traffic “gaps out,” the unused green time is given to the east- and westbound movement. With this timing, I believe we are providing a balance that best suits the needs of all users of the intersection.
Additionally, our Arterial Operations section is working with nearby business owners to explore removing parking eastbound on Admiral, approaching California. We believe this would help improve traffic flow.
I appreciate the patience from the community while we worked to resolve this problem. If you have additional questions or concerns, please feel free to contact me at traffic.signals@seattle.gov. Thank you for your input.
Before the WSB reports we linked above, discussion of the problem first surfaced in this WSB Forums thread.
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