Update on Project Design Changes

With construction on Polk Street’s two-year transformation underway, the SFMTA has made changes to the plan for a raised bike lane in light of recent agency research on best design practices. Additional street changes for the final design have also occurred since the final draft plan was presented to the public in 2014. 

The previous plan for the Polk Streetscape Project included a raised bike lane, with a two-inch mountable curb, on the northbound side of Polk from McAllister to Pine streets. The SFMTA is committed to building protected bikeways and wanted to better understand what street environments they are best suited for. A pilot raised bikeway was installed on Market Street in 2016 as part of an experiment to test different curb designs. A key finding from that experiment was that raised bike lanes on commercial streets like Polk are not sufficient to prevent drivers from parking in the bikeway.

To make the bike lane safer, the northbound bike lane will no longer be raised but will be built at road level with posts and a painted buffer zone to separate it from the traffic lanes. These measures will be more effective at deterring illegal parking and loading, and they will save on costs and time for construction. 

Additional design changes to the streetscape have changed from the 2014 final draft plan and today's 2017 final construction plan. These changes were presented to the public at the Van Ness and Polk Construction Open House in October 2016 and are largely due to unforeseen construction and maintenance costs.