What are Sharrows and How Should They be Used?

What are Sharrows?

Sharrows are white pavement markings showing a bicycle symbol with two chevrons on top (MUTCD). Some drivers think these lanes are dedicated bicycle lanes. You should know that bicycle lanes have a bicycle symbol and sometimes an additional diamond symbol. The diamond symbol indicates that it is a reserved lane.

When a street is too narrow to fit a lane for bicyclists only and too narrow for cars and bicycles to ride side-by-side, sharrows remind bicyclists and motorists that they must share the lane.

Oliver Gajda, the former Manager of a Bicycle Program in San Francisco, is credited with inventing the term sharrow. It is supposed to be a combination of the two words share and arrow, even if the arrows look more like chevrons.

Bicyclist May Use the Full Lane

A bicyclist may ride in the middle of a travel lane when necessary for safety, even with no shared-lane markings on the pavement. A bicyclist should always keep a safe distance from parked cars. A suddenly opened door can hit a bicycle and cause serious injury.

Sharrows serve as a reminder. They guide a bicyclist toward the center of a lane.

What Motorists Must Know

Motorists must know that a shared lane marking means bicyclists may use the entire travel lane. The motorist should slow down and keep a safe distance when approaching a bicyclist. The motorist should only attempt to pass in the same lane if it is safe to do so and there is enough room. Generally, a motorist should wait for a safe opportunity to move entirely into an adjacent lane.

You may sometimes see “Bicycles May Use Full Lane” signs along streets with sharrows.

Are Sharrows Effective?

Research indicates that shared lane markings increase operating space for bicyclists. But no studies suggest that sharrows are effective in reducing bicycle accidents. A 2016 study in Chicago shows that areas with sharrows installed were much less effective at reducing injuries per year per commuter than areas with bike lanes or no infrastructure.

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Manhattan photo by Jim Henderson