Evaluating the Effectiveness of the Minnesota Speed Management Program

Principal Investigator(s):

Kathleen Harder, Former Senior Research Associate, College of Design


Project summary:

The Minnesota Speed Management Program (MSMP), a cooperative project between the Minnesota Department of Transportation and the Minnesota Department of Public Safety, was developed within the framework of the Minnesota Comprehensive Highway Safety Plan as a means of reducing the number of fatal and life-changing crashes on Minnesota highways. The MSMP involved a speed limit adjustment; the speed limit was increased to 60 mph on 850 miles of Minnesota's 55 mph highways. It also involved periods of increased speed enforcement (one of six weeks, three of eight weeks) by State Patrol, county sheriffs, and local law enforcement on selected highways, each followed by four weeks of regular enforcement. MSMP involved extensive public education, organized by the Office of Traffic Safety, with approximately 10,000 public service messages presented on the radio. This project evaluated the effectiveness of the MSMP in order to help Mn/DOT and Mn/DPS decide whether or not to recommend an extension of the program. In collaboration with the two state agencies, researchers examined historical data, pre-test data, and data collected during four test periods in order to determine the initial effectiveness and first-year impacts of the MSMP. Two evaluation efforts were conducted. For the first, the University of Minnesota compared travel speed data and crash data obtained during the MSMP with historical data. Throughout the MSMP, there were decreases in the number of drivers traveling at least 10 mph above the speed limits: decreases of -28.7% on two-lane/two-way highways; -28.7% on four-lane divided highways; -42.9% on rural freeways; and -11.2% mph on urban freeways. The University's evaluation also showed there were reductions in the numbers of fatal and life-changing crashes during the MSMP. MarketLine Research conducted the second evaluation using telephone surveys, and found nine in ten drivers support the speed limit increase from 55 mph to 60 mph in both metro and greater Minnesota. The MSMP, in concert with other efforts that are part of the Minnesota Comprehensive Highway Safety Plan, resulted in reductions in the number of speeders on Minnesota Highways and reductions in the number of fatal and life-changing crashes, making Minnesota's roads safer.

Project details: