This paper presents some results of the collection of breath test data from a representative sample of roadside drivers in Minnesota State, USA. During two weeks in September 1990, voluntary interviews were conducted with 2857 drivers between 10pm and 3am in 16 Minnesota communities; the interviews were conducted in parking lots adjacent to roadways. Each driver remained in his vehicle during the 3min to 4min interview and breath test sequence. 96% of the drivers stopped agreed to be interviewed, and 98% of those completing the interview took the breath test. Table 1 gives the distribution of (equivalent) blood alcohol concentration (BAC) for the drivers who were interviewed and tested. Table 2 gives the proportion of drivers with BACs above 50 and 100mg/dl by sex, age group, time of week and time of night. One in 23 of the drivers were found to be legally intoxicated. Drivers were much more likely to have excessive BACs or to be legally impaired after midnight. The 21 to 24 age group had much the highest proportion of drivers with excessive BACs. Drivers leaving bars were found two to three times as likely to have a BAC, and also far more likely to be over the legal alcohol limit or have a very high BAC.
Abstract