Abstract
SWOV did research in 1976 into the depth of the tyre tread, because it was suggested in some publications that people often drove their cars with worn out tyres and because it seemed interesting to do this research just before the new law on tyre treads was layed down. The number of cars chequed was very small, so that it does not seem useful to do another investigation now to compare it with the one of 1976. furthermore there are now indications for an important change. Truck tyres were not considered.