Abstract
In two Dutch towns Groningen and Leeuwarden the police tested the condition of car tyres at random. In Groningen an intensive police control on tyre conditions was announced. After some weeks the tyres before tested in the two cities were tested again. In Groningen 54% of the drivers reviewed their tyres, in Leeuwarden only 27%. The control resulted to be very effective. Some of those who reviewed their tyres and who did not were interviewed, and their cars were tested. The results are described in this article.