Rumble Strips | Signage

Best Practices

This page contains guidelines on how facilities should be designed and built to best accommodate bicyclists. Where available, we'll include photos (and descriptions) of good and bad examples.
If you have any suggestions (or photos) please contact us!

Rumble Strips

Rumble strips are grooves or rows of raised pavement markers placed perpendicular to the direction of travel to alert inattentive drivers. As a vehicle passes over the rumble strips, noise and vibration are produced, alerting the driver they are approaching a hazard. [source: Washington State Dept of Transportation]

The problem for bicyclists is when these rumble strips take up too much of the shoulder so they cannot be avoided. While rumble strips merely create "noise and vibration" in a motor vehicle, they can cause damage to a bicycle and lead to a crash. Poorly placed rumble strips force bicyclists out of the shoulder and into the travel lane. Ideally, rumble strips should be placed on the fog line and leave at least 4 feet of usable shoulder (i.e., smooth surface not covered with debris). There also need to be periodic gaps in the rumble strips so bicyclists can move between shoulder and travel lane without having to ride across the rumble strip.

Thanks to Kent Peterson (Commute Director for the Bicycle Alliance of Washington) for the following photos of good and bad rumble strip placement:

BAD Rumble Strip	GOOD Rumble Strip
Bad rumble strips force riders into the travel lane, increasing conflicts with motor vehicles and reducing safety for all. If this rumble strip had been narrower and just ground into the fog line, the bicyclist would have been able to ride in the shoulder instead of in the travel lane with high speed motor vehicles.

Signage

Just as crosswalk signs serve a dual purpose both educating drivers to pedestrian rights AND to their presence on the roadways, bicyclists benefit from targeted signage in high conflict areas alerting motorists to their legal presence on the roadways.

In the few instances that signage has been used, the ambiguous "Share the Road" wording has not always been effective. Many drivers seem to interpret the sign to mean that bicycles should get out of their way. There are better signs that can be used to educate and inform road users. We recommend the use of signs that are more direct:

• [Bikes Allowed Use of Full Lane, Change Lanes to Pass]
• [Bicycles on Bridge Roadway]

Links:

• Bikes Allowed Use of Full Lane, Change Lanes to Pass Signs [San Fransciso Dept of Parking & Traffic]
• SAN FRANCISCO BIKEWAY DESIGN GUIDELINES

Rumble Strips | Signage