In 1990, the national and local police carried out an experimental integral traffic enforcement policy in the subregion of Leyden (situated in the western part of the Netherlands). The purpose of the experiment (See also IRRD 855463 and 855464) was to combine the enforcement on different important traffic offences as much as possible in order to increase efficiency. The experimental enforcement was concerned with: drinking and driving of road users, speeding, the use of seat belts, and the use of helmets by moped riders. Besides police enforcement, the experiment also consisted of publicity. The most important goal regarding the use of safety belts was to increase the use of belts on the front seat of cars to 90%. The enforcement on seat belt use was mainly carried out in combination with enforcement on speeding, and drinking and driving. About 7000 drivers were stopped of whom 277 drivers were fined for not wearing the safety belt. This number appeared to be only a fraction of the drivers who were observed while not using the seat belt. Most of them got a warning. Besides, a limited number of specific seat belt controls were conducted which actually did not fit within the concept of integral enforcement. The publicity was mainly directed at improving drivers' attitudes towards seat belt use. The effects of enforcement and publicity on belt use were investigated by means of a before and after study. About 5 months after the start of the experiment, 486 drivers who frequently travelled within the subregion of Leyden were surveyed by telephone in order to get some insight in their attitude towards belt use and their subjective chance of being caught for not using the belt. In the period between the before measurement in December 1989 and the after measurement in January 1991, the use of belts on the front seat of cars increased from 57% to 62%. This development favourably appeared to deviate from the national trend. However, the purpose to increase the belt use to 90% was not realized. Furthermore, a few observations done at the measurements of belt use generally appeared to correspond to the results of the national investigation: (1) Compared to drivers, occupants appear to wear the belt more often; (2) The belt usage for women is higher than for men; (3) The belt use among the 18-24 year olds is found to be the lowest; (4) In comparison with urban areas, the belt is more often used in rural areas, and particularly on motorways; and (5) a strong relationship is found between belt use by the driver and occupant (on the front seat). The results of the survey by telephone showed that also during the experimental enforcement the risk of being fined for not wearing the belt was - correctly - estimated by the public as being low. It is recommended to investigate the possibilities for more intensive publicity and education, mainly directed at novice drivers.
Samenvatting