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Speed Limits - Percentile Speed and safety

Does a speed limit set at the 85th percentile speed satisfy everyone?

Society expects behavioral consistency among those driving on our streets and highways. But drivers' skills, attitudes, and time pressures vary greatly, as does their perception of an appropriate speed limit. Whatever the speed limit, some will consider it too high; others, too low. What you should expect is that, within the latitude provided in Maryland law, engineers set the most appropriate speed limits on the basis of thorough study and the application of sound traffic engineering principles.

If motorists speed through a residential neighborhood, what should be done?

If the speed limit appears to be appropriate but speeders are creating a hazard, that calls for enforcement. Contact the law enforcement officers with jurisdiction over your street and ask them to check speeds and enforce the law.

If your street's speed limit itself seems unrealistically high, contact the traffic engineering agency with jurisdiction – all large political subdivisions have a traffic engineering office. If there is no such office, contact your law enforcement agency.

What if those steps fail to achieve appropriate speeds?

Some residential areas need slower speeds than posted speed limits. Traffic engineering studies can determine if "traffic calming" techniques, such as roundabouts, chokers, speed humps (not speed bumps), raised crosswalks, pedestrian refuge areas, or other physical controls, can reduce speeds and make your street safer.

Is it always safe to drive at the speed limit?

Speed limits are set for ideal conditions. Drivers need to respond to adverse conditions. Maryland vehicle law requires that motorists drive at a reasonable and prudent speed and with a regard for danger. Motorists must adjust their speed according to the existing vehicle and pedestrian traffic, road surface, lighting, and weather conditions. You should always maintain a safe speed.

MARYLAND DEPARTMENT OF TRANSPORTATION

State Highway Administration
Office of Traffic and Safety
Traffic Safety Division
410-787-5822