Monday, October 4, 2010

40% Fewer Motorists Block Green-Painted Fell Street Bike Lane in SFMTA Study

Bike lane on block of Fell Street painted green in August 2010

Forty percent fewer motorists blocked the Fell street bike lane near the Arco service station once the city painted the lane green, according to a study conducted by the San Francisco Municipal Transportation Agency (SFMTA). Of all the motorists waiting to enter the gas station before the green paint was applied, 25% blocked the bike lane. After the green, 15% of all the motorists queuing up for gas obstructed the bike lane. The change represents 40% fewer motorists in the way of westbound bicyclists. As one traffic engineer observed, "In the greater context of it, that's a pretty effective drop in blocking of the bicycle lane for something as 'simple' as coloring it."

In June of this year the SFMTA removed several parking spaces along Fell near the entry and exit of the Arco station to create a curb-side queue for motorists waiting to purchase gas. In August the SFMTA painted the city's second green bike lane to encourage safer passage for cyclists. Anecdotal evidence of the effectiveness of the interventions has been mixed. Removing the parking spaces opened up a long stretch of Fell and improved visibility for motorists, bicyclists, and pedestrians. Several bicyclists have observed greater ease traveling between Scott and Divisadero, but many others describe the traffic improvements as minimal and intermittent. No one would be hard-pressed to find instances of motorists partially or fully blocking the bike lanes, green or not. Every Friday during the evening commute, the grassroots group Fix Fell stages a protest on Fell with the intent of doing so every week until the city closes the Arco entry and exit. Now the SFMTA has presented data that, in effect, reflects both views: a 40% reduction is a considerable improvement, but much of the problem remains.

In the months ahead, more motorists may keep the green lane clear as they notice others doing so, but a cumulative effect it is difficult to predict. Little traffic enforcement has been observed on Fell near Arco -- at least none to keep drivers out of the bike lane. SFMTA interns informed motorists of the changes on Fell this summer, but the outreach has been discontinued. The only other major traffic design changes being discussed for Fell Street are the removal of the Arco curb cuts, the installation of a separated bikeway, or cycle track, from Scott to Stanyan streets, and the possibility of returning Fell to a two-way street.

The SFMTA study of this one block of Fell adds more data and local experience with the positive impact green bike lanes can bring to public safety and traffic flow. Market Street features the only other location of green-painted lanes in the city. The SFMTA plans to extend the green stripe on Market all the way to the Embarcadero, but not as quickly as the San Francisco Bicycle Coalition has urged, as reported in Streetsblog.

A minor note: The description of the study of the Fell green bike lane on the SFMTA website (scroll to mid-page) inaccurately reports 10% fewer motorists blocking the bike lane since it was painted green. The mistake reflects a misreading of the 25% and 15% findings mentioned in the first paragraph above. The relevant equation, for those inclined, is 1-(15/25) x 100.
1:15 pm Tuesday update: The SFMTA description of the study has now been updated.

Thanks to BIKE NOPA reader "S.N." for alerting me to the SFMTA report.


  1. This is great news! I was struck by a car in this bike lane at the entrance to Arco. Thanks for the update.

  2. e: If you're willing to share the information, it would be helpful to know the particulars of the collision. Hope there was no injury involved.

  3. Not perfect but better is my observation as well. Thanks to all the shades of activism that have contributed to this improvement, and hoping we can continue to make progress at this critical stretch of bike route.

  4. Thanks for this update Michael! It's really great to have some hard evidence about how the change has affected this critical bikeway for thousands of riders.

    I do want to note that the Wigg Party and Fix Fell are both calling for making the turn off of Fell onto Scott illegal for motorists. This would make that dangerous turn onto Fell for bikers MUCH safer.