A statistical analysis of seat belt effectiveness in 1973-75 model cars involved in tow-away crashes

  • Published: DOT HS 802 035, 1976
  • Authors: Donald W. Reinfurt, Claudio Z. Silva, Andrew F. Seiva
  • Date Added: 01 Feb 2013
  • Last Update: 01 Feb 2013
  • Format: pdf

Objectives:

To calculate an accurate assessment of the effectiveness of seat belts at preventing injury by overcoming several of the data collection issues which biased previous results.

Methodology:

Detailed information was collected on over 15,000 towaway accidents involving 1973-75 model passenger cars from 5 sites in theUSA. Standardised injury rates were calculated, and compared in order to establish seat belt effectiveness. Confounding variables between the groups were corrected in the statistical analyses

Key Findings:

  • The study examined the effectiveness of seat belts at preventing injuries which were judged to be ‘moderate’ severity and above.

  • Compared with unrestrained occupants, using a lap belt reduced the injury rate by 31%.

  • In frontal impacts the rate was reduced by 23%, and in side impacts it was reduced by 40%.

  • Compared with unrestrained occupants, using a three point belt reduced the overall injury rate by 56.5%.

  • In frontal impacts the rate was reduced by 53%, and in side impacts it was reduced by 59%.

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