Abstract
This paper presents onboard computer systems (black boxes), that: (1) contribute to road safety by helping to reduce the number of accidents; and (2) provide data for accident analysis based on field experiences in USA and Europe with case studies. There are several versions of onboard computers that record the performance of drivers and vehicles. Field experiences and case studies show that a 'feed back' of these records lead to a favourable modification of drivers' behaviour. Further these objective and accurate recordings allow detailed reconstruction and analysis of accidents.