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Case Study

Market Street Protected, Buffered Bicycle Lane, San Francisco, CA

City: San Francisco
State: CA
Associated Publication: Urban Bikeway Design Guide

Market Street is a busy commercial corridor that is vital to multiple modes of surface transportation. Diesel buses, trolley coaches, and light rail vehicles share the roadway with delivery trucks, taxis, private automobiles, and bicycles. While competing demands for roadway use have been addressed by providing transit only lanes and bike lanes, commercial vehicles, taxis, and private motorists regularly use the sidewalk or bike lane for loading and unloading. Vehicles that encroach into or stop within the bike lane create a safety hazard, forcing cyclists to swerve out into the travel lane to avoid the obstructing vehicle and thereby contributing to unnecessary delay on already-busy Market Street and endangering cyclists.

In response to these issues, as part of a pilot project in May 2010, the San Francisco Municipal Transportation Agency installed traffic channelizers, or “safe-hit posts,” along Market Street between Gough and 8th Streets where a painted buffer already existed in the space between the bike lane and travel lane.  These surface-mounted, retroreflective traffic control devices discourage motorists from crossing into the bicycle lane.  In addition to channelizers, parts of Market Street’s bicycle lanes were painted green to “brand” the lanes and further increase their visibility. Because Market Street is particularly complex and home to so many different modes of transportation, there is no consistent bicycle treatment along its length.  While green buffered lanes are lauded by San Francisco cyclists, there remain stretches with shared lanes rather than dedicated bike lanes.

Until Fall 2010, San Francisco was subject to a court-ordered injunction prohibiting the implementation of new bicycle-related improvements.  While the Bicycle Plan Injunction was partially lifted prior to this project, the number and type of projects permitted was still limited.  Additionally, the use of colored pavement as a traffic control device is not officially sanctioned by the Federal Highway Administration.  Therefore, the Market Street colored bike lanes have not been made retroreflective, and the SFMTA’s official position is that the color is not serving as a traffic control device; it is serving merely an aesthetic “branding” function.

Before-and-after observations of bike and vehicle traffic were conducted in January 2010 (before the channelizers and green paint) and in October 2010 (after the treatments) along one westbound segment and four eastbound segments. These observations show an 84 percent reduction in the number of vehicles encroaching in the bike lane.  Intercept surveys conducted in May 2010 (before the green paint) and October 2010 (after the green paint) showed mixed results in perception of the green lanes, with a 9 percent increase in safety ratings among eastbound travelers but no change observed by travelers intercepted as they were headed westbound.

Market St. Plans 1

Market St. Plans 2