Why and How!
Maryland's State and local traffic engineers receive requests to raise, lower, or simply review speed limits on streets and highways throughout the State. This brochure is intended to help our citizens, elected officials, communities and other interested parties understand speed limits, how they are set, and how they affect traffic and safety.

How are speed limits set?
Basic speed limits for various streets and highways are set by Maryland vehicle law. However, in many instances, these statutory limits do not account for actual highway and traffic conditions important in the safe and efficient movement of traffic. Thus, the law provides that these limits can be raised or lowered based on the results of traffic engineering studies.

What conditions influence speed limits?
Speed limits often are set higher or lower than the statutory limits when one or more of the following circumstances are present:

• Atypical traffic characteristics because of particular land use or other conditions.
• Road design elements substantially above or below what are typical.
• Prevailing speeds consistently higher or lower than the statutory speed limit.
• Transition between rural and urban areas on major highways.
• Schools or other significant pedestrian traffic areas.
• Road construction activity.
• Frequent collisions in which speed is a contributing cause.
• Unusual or unanticipated conditions.

After a speed limit is established, changes in these circumstances could prompt further traffic engineering study to determine if it needs to be raised or lowered.