THE 55 MPH SPEED LIMIT AND FATALITY REDUCTION IN UTAH

This study attempts to determine whether the 55 mph speed limit can be identified as a primary factor in the fatality reductions recorded in 1974 and 1975. Available data is subjected to statistical analysis by testing the hypothesis that the sample means are equal and any differences observed are due to statistical chance. Data from 1971-1973 is analyzed and compared with separate data from 1974-75. Results indicate that the imposition of the 55 mph speed limit and other factors existing in 1974 caused a significant reduction in fatalities on facilities where the speed limit was reduced. The reduction in 1975 (compared with data from 1971-73) was also significant but not as great as in 1974. The author concludes that the factors causing the dramatic decline in fatalities in 1974 were not as effective in 1975.

• Corporate Authors:

  Institute of Traffic Engineers

  2029 K Street, NW
  Washington, DC    20006
• Authors:
  • Labrum, W D
• Publication Date: 1976-9

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 13-16
• Serial:
  • Traffic Engineering
  • Volume: 46
  • Issue Number: 9
  • Publisher: Institute of Traffic Engineers

Subject/Index Terms

• TRT Terms: Fatalities; Hypothesis testing; Speed limits; Statistical analysis; Traffic control; Traffic crashes
• Uncontrolled Terms: Hypothesis
• Subject Areas: Data and Information Technology; Highways; Operations and Traffic Management;

Filing Info

• Accession Number: 00141661
• Record Type: Publication
• Files: TRIS
• Created Date: Dec 15 1976 12:00AM