One of the most important items in accident reconstruction and analysis is the sequence of events and manoeuvres prior to the collision. Whereas some of this information is available in the raw police file, it is generally lost in the process of coding the statistical computerised accident records which form the basis for most remedial work. It is therefore a widespread habit to return to the police files for detailed analysis. This is a time-consuming and sometimes impossible task, seriously limiting the quality of accident research. A feasible solution is a computerised accident report which contains the vocabulary used by police investigators, and varies according to the accident patterns under investigation. As a first application, one type of accidents was studied - single-vehicle accidents with injury on non-urban roads. For this, detailed descriptions of 170 accidents were collected through the police files, within the Haifa Police District in Israel for the period 1989-1992. From the unrestricted verbal description used in the police files, a computer-fitted form was developed, with the aid of which the set of accident descriptions was converted into a database file. Manipulation of the database records yielded 16 accident patterns. They are defined mainly by pre-crash vehicle manoeuvres, but also by tendencies in driver's motivations and road specifics. On average, an accident studied includes 2.7 steps, i.e., vehicle manoeuvres, prior to the final event - vehicle "stopped" or "overturned". The single-vehicle accident mechanism was examined in detail with regards to accident severity, final state and manoeuvre regularities. (A)
Abstract