While there is consensus that crash severity increases with speed, the precise relation between travel speed and crash probability is less clear with various studies coming to different conclusions.  One of the main deficiencies in studies to date is the lack of accurate knowledge of the travel speed before crashing.  Scientific evidence of the relation between speed and safety will be needed to mount convincing and effective speed management campaigns.

Key Actions:

• Research the relationship between travel speed and crash risk on various road types.  (Planned, 2 years)

• Develop a typology for speeding-related crashes.  (Planned, 1 year)

Good speed and crash data are critical to better understand the speeding problem and make wiser decisions on where best to concentrate resources in order to have the most effect in reducing speeding related injuries and fatalities.

Key Actions:

• Compile and report annually in the Traffic Safety Facts series information on the scope and nature of speeding involvement in traffic fatalities.  (In progress)

• Working with the States, and local agencies as necessary, monitor and report travel speed trends across the entire road network.  (Planned, 2 years)

• Identify States and road types where excessive and inappropriate vehicle speeds are a safety problem.  (Planned, 1 year)

• Work with States to ensure they identify jurisdictions and road types where excessive vehicle speeds are a safety problem.  (Planned, 2 years)

Additional research is needed on the spillover and net safety effects associated with speed limit changes for both limited- and nonlimited-access roads.

Key Actions:

• Monitor changes in State speed limit laws and posted speed limits.  (In progress)

• Evaluate the long-term effects of raising and lowering speed limits on speed and crash risk.  (In progress)

• Evaluate the effects of differential limits for cars and trucks.  (In progress)

• Evaluate the effects of minimum speed limits.  (Planned, 3 years)