Research Rest-Stop │ “Sharrows” and Sharing the Road

Sharrows on Ridge Avenue close to the Lincoln Drive/I-76 Interchange

Every Wednesday, the Mayor’s Office of Transportation and Utilities (MOTU) highlights some interesting research related to or innovations in transportation, sustainability, or energy. This week’s Research Rest-Stop looks at the development of “sharrows” in the urban environment.


“Sharrows,” which derive their name from the combination of “arrow” and “share the road,” provide visual cues to bicyclists and motorists to share roads with each other. While sharrows have gained popularity in the last several years, they received much support in 2009 when the Federal Highway Administration included the term in its Manual on Uniform Traffic Control Devices (MUTCD).

As cities increasingly promote sharrows, concerns have grown. Some of the first cities to support sharrows such as Sacramento and Baltimore originally had the markings to the far right sides of the road, which placed bicyclists often in conflict with people leaving their parked automobiles. Today, federal regulations require a four foot space between sharrows and curbs without parking and eleven feet between curbs with parking.

Despite these concerns, sharrows are a relatively simple and inexpensive way to promote “road-sharing.” They cost roughly $229 each to install, including all labor and maintenance costs, and serve as good alternatives to more expensive bike lanes that can often run between $5,000 and $60,000 per mile depending on the design and construction.

The effectiveness of sharrows, however, is often a topic of discussion. A recent study demonstrates that sharrows slow down car traffic slightly and improve bicyclist safety while significantly helping drivers stay farther away from parked cars. Despite this, many argue that sharrows serve more of a way-finding purpose than a safety one.

No matter one’s opinion of sharrows, the markings clearly serve as the first steps in a city’s efforts to support walking and bicycling in neighborhoods. In Philadelphia, the Streets Department has established a sharrow installation program on major bicycle routes throughout the city. Sharrows now exist along Umbria, Main Street and Ridge Avenue between Manayunk and the Wissahickon. Sharrows also exist on Ridge from the Wissahickon Creek to Kelly Drive in East Falls, courtesy of PennDOT.

For more information, please see “Sharing Time: Tracking the ‘Sharrow’ on City Streets.” Image above can be found at “Sharrowdelphia – Streets Dept. Begins Its Sharrow Installation Program.”


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