The effect of increasing rural interstate limits in the USA

Within a year of the repeal of the National Maximum Speed Limit in the United States of America in 1995, 23 states had raised their rural interstate speed limits to 70 or 75 mph. The effect on rural interstate fatalities was examined by modelling fatalities between 1992 and 1999 against the size of the new speed limit, the period before and after the speed limit change, and their interaction. Fatalities in the groups of states that raised their speed limits to 75 mph and 70 mph were 38 per cent and 35 per cent, respectively, higher than expected based on fatalities in the states that did not change their speed limits. Furthermore, the states that raised their speed limits to 75 mph had a higher rural interstate fatality rate before the speed limit was changed than the other groups of states. The changes in fatalities were less than those one would predict if the speeds had changed by the amount of the speed-limit change. This could be related to already-high speeds in the limit-changing states. This view is corroborated by some speed survey data and is consistent with the already higher crash rates of the limit changing states.


  • English

Media Info

  • Pagination: 12p
  • Monograph Title: IPENZ Transportation Group Technical Conference papers 2002

Subject/Index Terms

Filing Info

  • Accession Number: 01387603
  • Record Type: Publication
  • Source Agency: ARRB
  • Files: ATRI
  • Created Date: Aug 23 2012 12:14AM