A STATISTICAL ANALYSIS OF THE EFFECT OF THE 55 MPH MAXIMUM SPEED LIMIT ON HIGHWAY SAFETY IN UTAH

This effect to quantify Utah's statistical data on the 55 mph speed limit utilized the fatility rate as a measure of effectiveness. The faility rate which designates event (accident) and also severity (fatality), is reduced to a comparative common denominator - fatalities per 100 million vehicle miles. The analysis is further quantified by comparing fatality rates in affected areas (change in speed limit) and unaffected areas (no change in speed limit). Comparison is also made between years of no speed change (1972-73) and for years of no speed change vs. speed change (1973-74) and for years of speed change (1974-75). Comparative data is tabulated. Analysis of the fatality rates suggests only a slight speed change safety improvement through 1974 after discounting fatility rate improvements for no speed change areas and expected improvements administered by other programs. Extension of the analysis into data for 1975 indicates a negative safety improvement in speed change areas. Additional analysis also indicates a lower fatality rate in the speed change areas. It is inferred from this that the speed change was not the contributory link in Utah's highway safety improvement. Reasons are suggested for Utah's reduced fatalities which coincided with the 55 mph speed limit.

  • Corporate Authors:

    Institute of Traffic Engineers

    2029 K Street, NW
    Washington, DC    20006
  • Authors:
    • Geurts, C A
  • Publication Date: 1976-1

Media Info

  • Features: Figures; Tables;
  • Pagination: 3 p.
  • Serial:
    • Western
    • Volume: 30
    • Issue Number: 2
    • Publisher: Institute of Traffic Engineers

Subject/Index Terms

Filing Info

  • Accession Number: 00134014
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jun 23 1976 12:00AM