The National Highway System Designation Act of 1995 repealed the national maximum speed limit (NMSL) and returned authority to set speed limits to the states.
When the national maximum speed limit was repealed, the Iowa Safety Management System Coordinating Committee formed a Speed Limit Task Force to provide information to legislative decision-makers on the subject of speed limits. That task force has issued reports on the subject of speed limits in 1996, 1997, 1998, 1999, 2000, and 2001.
Higher Iowa Speed Limits Authorized in 1996
Iowa law was amended in 1996 to authorize the Iowa Department of Transportation (DOT) to increase speed limits to 65 mph on certain divided multi-lane highways.
Engineering Studies Preceded Iowa Changes
Before any changes were made in Iowa, the Iowa DOT undertook an engineering review of highways eligible for increased speed limits under the new law. A total of 355 miles of rural, four-lane divided expressways were included in the review. As of January 2001, the speed limits were increased to 65 mph on more than 631 miles of Iowa freeways and expressways.
The 2001 report included here is a compilation of data gathered in Iowa and other states regarding the effects of changing speed limits on travel speeds, crashes, injuries and fatalities. Older reports are also available.
For Further InformationTo obtain more information concerning these reports, or the earlier ones, contact:
The draft of the plan is available on this site in Adobe AcrobatTM (PDF) format.
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by Michael D. Pawlovich