Police have warned drivers to make sure their tyres are fit for use after carrying out checks at a car park.
Officers visited Churchill Square shopping centre car park in Brighton and examined the tyres of more than 400 vehicles.
Thirteen vehicles had defective tyres, most of which had tread of less than 1.6mm.
The vehicles’ details were recorded and Tyresafe leaflets were left for the owners as well as Sussex Safer Roads Partnership forms advising them that their tyres needed to be changed immediately.
PC Phil Barrow said: “We chose Churchill Square because it allowed us to check far more vehicles than if we had been stopping vehicles by the roadside. It also meant that we did not have to unnecessarily delay any motorists whose vehicles were in a good condition.
“Having good tread on your tyres can be the difference between your vehicle gripping the road and it not, when you drive onto a slippier part of the surface.
“It could be what prevents you from skidding off the road or into another motorist and causing a serious crash.”
A police spokesman said tyres should be checked at least once a month and before any long journeys. This should include the air pressure, overall condition and that the tread depth is at least 1.6mm across the central three quarters of the tyre and around the whole circumference for cars. A quick way to check the tread is to use a 20p piece.
Further unannounced tyre checks are planned for January and throughout the year.