Tool Box
Neighborhood Traffic Management Program

SPEED LUMP

The speed lump is a variation on the speed hump, adding two wheel cut-outs designed to allow large vehicles, such as emergency vehicles and buses, to pass with minimal slowing. The design limits passenger cars and mid-size SUVs from fully passing through the cutouts, but allows one set of wheels to pass through the cut-out while the other set is required to travel over the lump.

The magnitude of reduction in speed is dependant of the spacing of speed lumps between points that require drivers to slow. Speed lumps have a similar reduction in speeds when compared to speed humps.

Advantages

• Effective in reducing speeds
• Maintains rapid emergency response times
• Relatively easy for bicyclists to cross

Disadvantages

• Vehicles with wide wheel base can pass through the lump using the wheel cutouts
• Increased noise
• Aesthetics
• Signs may be unwelcome by adjacent residents

For additional information please contact:

Tracy Whitley
Project Engineer
Sacramento County Department of Transportation
whitleyt@SacCounty.net