A comparison of all Driving While Intoxicated (DWI) trips with the number of DWI trips detected by the police provides a 'dark number' of DWI trips. 4 components are identified a) DWIs not stopped by the police and not involved in an accident, b) DWIs stopped by the police but the intoxication not noticed, c) DWI trip leads to an accident but the police not called and d) DWI leads to an accident but the intoxication not noticed by police. Methods of determining the numbers involved, and thus preventative strategies, are discussed. A method is then suggested based on the German Roadside Survey of 1992-4. The results obtained are discussed. A figure of 100 million DWI trips a year is suggested of which 700,000 are detected. Strategies to improve the detection of dark DWI trips are considered.
Samenvatting