Shared Lane Pavement Markings

• What are Shared Lane Pavement Markings?
• Why are these markings on the street, what is their purpose?
• Why not just stripe bicycle lanes?
• As a cyclist, what should I do in the presence of these markings?
• As a motorist, what should I do in the presence of the shared pavement markings?
• Why not put the markings on all busy streets?
• Do the shared lane markings work?

What are Shared Lane Pavement Markings?

They are road markings to indicate that motorists and cyclists must share the travel lane. They are sometimes referred to as “sharrows.”

Why are these markings on the street, what is their purpose?

The purpose of the markings is to create improved conditions for bicycling, by clarifying where cyclists are expected to ride and to notify motorists to expect cyclists on the road. In the absence of bicycle lanes, motorists often neglect to share the travel lanes safely with cyclists, and cyclists feel compelled to ride closer to parked cars. If somebody were to open a car door as a cyclist passed the cyclist could get “doored.” Also, when cyclists stay to the far right in narrow travel lanes, passing motorists often pass too closely to the cyclists. This is not only unnerving for the cyclist, but leaves little margin for error.

Why not just stripe bicycle lanes?

Shared markings are used when there isn’t enough room on the street for bicycle lanes. Bicycle lanes are still the best treatment for creating safe and comfortable conditions for bicycling on busy streets. We will consider using shared lane pavement markings only after evaluating all possibilities for installing bicycle lanes.

link to further information on the benefits of bicycle lanes

As a cyclist, what should I do in the presence of these markings?

The markings are placed approximately where cyclists should be riding. Cyclists should stay in the middle or to the left of the markings.

As a motorist, what should I do in the presence of the shared pavement markings?

Slow down and drive carefully. Because the travel lane is too narrow for safe side-by-side travel by motorists and cyclists, motorists should slow down and either wait for the cyclist to turn off the roadway, or wait until s/he can move into an adjacent travel lane.

Why not put the markings on all busy streets?

Right now we’re studying them as part of a Federal Highway Administration evaluation process. We will expand the use of the markings on other streets in the city once the evaluation is complete and supports that strategy.

Do the shared lane markings work?

A 2003 study in San Francisco showed that in the presence of the markings cyclists moved further away from parked cars and passing motorists moved further away from cyclists than in the absence of them. The study we are doing should be completed by the end of 2008.

For More Information

For more information about bicycling in Cambridge, please contact Cara Seiderman, cseiderman@cambridgema.gov, at 617/349-4629. The Community Development Department TTY line is 617/349-4621.

 

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