Wednesday, November 10, 2010

New Bike Light Shield at Fell & Masonic: Small Change Might Reduce Crashes

With the shield, drivers see the no-turn arrow but not the green bike light to the left

The bike signal lights are obscured from the view of drivers in turning lane

Previously, drivers saw both red and green lights at the same time

Enforcement needed here: some drivers ignore all signals (1pm Nov. 9)

Without fanfare or even an announcement, the San Francisco Municipal Transportation Agency (SFMTA) has installed a shield to the bike light at the intersection of Fell and Masonic. The small adjustment may reduce the risk of collisions for travelers who use the intersection. The shield -- actually metal slits within the housing of the bike light -- obscures motorists' view of the bike signal so they don't think a green bike light allows a left turn from Masonic even with a visible red no-left-turn arrow.

Several collisions occurred at the crossing involving motorists and bicyclists and motorists and pedestrians before the bike light was installed in September 2008, and crashes continued to happen afterwards. Pedestrian and bike advocates have suggested that motorists may get confused by the combination of a red turn arrow and the green light meant only for bicyclists using the crosswalk. They began urging an adjustment within weeks of the initial light installation. Two years later, cyclists noticed the new shield on Monday of this week.*

A stop at the intersection early this afternoon indicated that drivers waiting in the left turn lane were unable to see the bike light. (I asked two motorists waiting for the light since I traveled by bike and did not approach the intersection in a vehicle). However, as happens frequently at the intersection, a truck driver did not see or ignored the red turn signal and nearly hit two cyclists crossing with a green light. As much as the new light shield may reduce collisions, the real solution for safe passage for bicyclists and motorists is to install separated bikeways on Oak and Fell for east-west travel.

Correction: An earlier version of this article listed the date of the bike light installation as January of 2008; the light was installed September 2008.

* Thanks to Marc Caswell, Fix Masonic coordinator, Masonic resident, and SFBC staffer for sharing his sighting of the new shield.

For other stories in the A Better Masonic series, check here.


  1. Thanks for this!
    I'm not sure I agree with separated bikeways on Oak and Fell. Those streets are too fast, separated or no, and we'd still be exposed to traffic at each intersection! How about returning Oak and Fell to two-way to calm things down for a start?

  2. I'm totally in favor of the separated bikeway. Take the unnecessary 4th driving lane between Baker & the Golden Gate park and turn it into a bike path plus a sidewalk next to the park.

  3. Perfect example of a small change that makes a big difference.