The efficacy of drinking-driving countermeasures can be assessed in several ways, including reported changes in attitudes and behavioral intent as well as changes in crash rates. However, few studies have examined the changes in actual drinking-driving behavior. A method of surveying the blood alcohol concentrations (BACs) of drivers, without either police intervention or disruption to traffic flow, was developed in South Australia. This method, which has been used successfully to test approximately 50,000 drivers, is described in detail. The method involved investigators from the NH and MRC Road Accident Research Unit who asked a sample of drivers stopping at traffic lights to undertake a breath test. Each survey team comprised one male and one female investigator. One of the investigators approached the driver of the first car to stop at a red traffic light and tells him or her that they are from the University of Adelaide Accident Research Unit, that they are not the police, and that they are measuring breath alcohol concentrations of drivers as part of a study of drinking and driving in Adelaide. The driver was asked to blow through a tube attached to a handheld breath alcohol meter and was also handed a reply paid questionnaire focusing on drinking and driving. The entire process took less than 25 seconds. The sex of the driver, an estimate of his or her age and the total number of occupants in the car were also noted. A traffic count was also undertaken to ascertain the percentage of drivers sampled.
Abstract