The Glen Park Association Transportation Committee asked SFMTA for an update on the Diamond/Bosworth intersection. SFMTA’s estimations and updates are below:
GPA: What is the progress on Phase 1 (Diamond/Bosworth intersection in terms of final striping and signals?
Phase 1 completion: permanent striping was completed. Our signals shop is currently installing the final pieces for the new traffic timing card. They estimated that the new traffic signal would be turned over between the weeks of May 31 to mid-June. Right now the signals are still taped over. That will be removed once the final traffic timing is turned on.
GPA: What is the update on Phase 2 (Arlington/Bosworth) funding?
Our Livable Streets division is still looking for funding for Phase 2.
GPA: What did you learn about installing a protected left turn from SB Diamond onto EB Bosworth?
Our traffic engineers looked over the potential left-turn from SB Diamond onto EB Bosworth and concluded that adding the left-turn phase would create longer vehicle queues in all directions and bring down level of service (LOS) grades.
I’m working with the traffic engineers to provide the analysis that was used and format it for your review. This turn phase has been requested several times, and each time we respond with a similar conclusion as to why it’s not good for the intersection. I want to show the group what the engineers look at when they analyze these requests to show where our concerns are coming from. The engineers have put together a video simulation of what the traffic currently looks like during the busiest time of day, the AM rush hour peak, and what it may look like with the left-turn phase added. We can mail the materials to the GPA or meet in person (in Glen Park or SFMTA office) to discuss the analysis. Let me know what the GPA’s preference is.