Samenvatting
Three roadside surveys of drivers in Washtenaw County, Michigan were conducted in March of 1971, 1972 and 1973. The surveys were an integral part of the evaluation procedures for the Washtenaw County Alcohol Safety Action Program (WCASAP) and were designed to obtained representative samples of nighttime driving residents. The major conclusion to be drawn from the three surveys is that the proportion of drivers with measurable BAC decreased each year. In 1971, 19% of the drivers had positive BAC, decreasing to 15% in 1973. Over the same time period, the proportion of drivers with BAC of 0.5 or higher decreased from 10% to 8%. (See also B- 4041).