The 1975 roadside survey of drinking and driving, the fifth in a series of annual surveys, was held the last two weeks of October. Following a new procedure tested in the 1974 survey, randomly selected motorists were given a brief interview and a breath test at their cars. The new, NHTSA-developed portable breath testers were used successfully except for power supply problems with one unit. Two crews worked concurrently Wednesday through Saturday nights, from 7:30 PM until after 2:00 AM at 15 locations in Kansas City. A total of 1,059 drivers provided breath samples and answered the questions, for a cooperation rate of nearly 96%. Overall, 26.9% of the drivers had been drinking, as indicated by the breath tests, and 4.9% would have been presumed intoxicated under the state laws of Missouri (blood alcohol content--BAC--of 0.10% or greater). These percentages are below those obtained prior to ASAP (29.2% and 5.5%), but higher than in 1974 (26.5% and 4.2%). The percentage of very high BACs (0.15% or more) remained at the 1% level obtained the previous 2 years, which was significantly less than the 2% pre-ASAP level. As in previous surveys, drinking behavior increased significantly later in the evening, and to some extent depended on the day of the week. Therefore, the data of this year and of the 4 previous years were adjusted to account for differences in sample sizes by time of day and day of week. The adjusted data also show a recent regression toward Pre-ASAP drinking and driving patterns. They also show an increase in moderate drinking levels (BAC of 0.05% to 0.09%), to nearly 11% (adjusted) of the nighttime driving population, the highest such percentage yet observed. No charges in sampling procedures or in the demographic characteristics of the respondents could be shown to be responsible for the apparent recent increase in drinking and driving. However, several factors were noted that appear to be related to the changes. Although people's self admissions of their alcoholic consumption had not changed, the percentage of nighttime drivers coming from bars and restaurants increased 35 to 40% over the 1972-1973 figures. Thus, people may not be drinking more, but they may be doing it more in public and, therefore, in conjunction with driving. A startling increase in drinking and driving among tennagers was found. Not only are tennagers accounting for an ever increasing fraction of the nighttime drivers (14% in 1975), but 1 out of 5 of them had been drinking.

  • Supplemental Notes:
    • Sponsored by the City of Kansas, Missouri, and the Department of Transportation.
  • Corporate Authors:

    Midwest Research Institute

    425 Volker Boulevard
    Kansas City, MO  United States  64110-2299
  • Authors:
    • Glauz, W D
    • Sharp, M C
  • Publication Date: 1976-4-9

Media Info

  • Features: Figures; Tables;
  • Pagination: 67 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00141009
  • Record Type: Publication
  • Source Agency: Highway Safety Research Institute
  • Report/Paper Numbers: Special Report No. 13
  • Contract Numbers: DOT-HS-077-1-100
  • Files: TRIS
  • Created Date: Oct 6 1976 12:00AM