The annual total of vehicle miles travelled is generally accepted as a measure of risk exposure. A combination of different data sources used in Germany in 1990 and 1993 to obtain exposure estimates is described. Vehicle mileage is determined for certain subgroups of vehicles and types of vehicle trips. The main elements of the system consist of a nationwide vehicle mileage survey, a diary-type survey of vehicle usage, a survey of vehicle mileage in border-crossing traffic and traffic counts on German roads outside built-up areas. Vehicle mileage is also calculated from fuel consumption data. Some statistical aspects of the nationwide vehicle mileage survey are presented with a brief outline of the steps involved in its planning and execution.
Abstract