THE SPEED OF CARS WITH AND WITHOUT STEEL STUDDED TYRES ON A DRY ROAD

TRAFFIC COUNTS AND SPEED MEASUREMENTS WERE CARRIED OUT ON THE KARLSRUHE - BASLE MOTORWAY ON SUNDAYS IN JANUARY AND MARCH 1971. WHEN SPEEDS WERE FAIRLY LOW NO DIFFERENCES IN BEHAVIOUR WERE OBSERVED BETWEEN THOSE VEHICLES FITTED WITH STEEL STUDDED TYRES AND THOSE WITHOUT STEEL STUDDED TYRES. HOWEVER, AT HIGHER SPEEDS, AND PARTICULARLY WHEN WEATHER CONDITIONS AND CONDITIONS ON THE ROAD WERE GOOD, SIGNIFICANT DIFFERENCES IN BEHAVIOUR WERE OBSERVED; IT WAS FOUND THAT IN GENERAL VEHICLES FITTED WITH STEEL STUDDED TYRES TRAVELLED AT HIGHER SPEEDS. IT IS RECOMMENDED THAT FURTHER RESEARCH BE CARRIED OUT TO DETERMINE THE EFFECT OF THESE HIGHER SPEEDS ON SAFETY AND ON THE LIFE OF THE ROAD SURFACING.