The observation of safety belt use can be performed at a distance (AMA), or by looking inside the car (IMA). The aim of this study is to get an insight into the reliability of the AMA method in comparison with the IMA method. Both methods were used in 1990 to observe the safety belt use on front seats of cars. These methods were applied simultaneously at 8 locations within and outside built-up areas in the Netherlands. The AMA observer noted: (1) the seat belt use by and sex of both drivers and front seat passengers of cars, as many as possible, while these were waiting at traffic lights; and (2) the first four characters of the cars' licence number. The AMA allows more observations than the IMA method, as the cars waited at traffic lights. The overall results of both methods show that the AMA method appears to be appropriate to carry out overall measurements of seat belt use on the front seats of cars, and possibly of the occupants' sex. However, more certainty is required about the AMA's reliability for a number of specific conditions, for instance, certain road types within built-up areas. More attention should be paid to the observators' instructions. The AMA is a cheaper alternative for the IMA method, provided that its observations' reliability is improved sufficiently.
Abstract