REPORT OF SUBCOMMITTEE ON TIRES, VEHICLES, AND VEHICLE COMPONENTS

Opportunities for implementing improvements take place almost automatically in competitive industries such as vehicle and tire manufacturers. Therefore, there has been no formal implementation program of those things learned in the 19 years since the First International Skid Prevention Conference. As improvements became available, they were adopted immediately. Since the first international conference, the tire industry has just about doubled the wet coefficient of tires on slippery roads and at the same time doubled tire life. One matter, however, that the tire manufacturers could not deal with and that needs immediate attention is the matter of laws governing minimum tread depth. In a panel discussion during the second international conference, John R. Treat of Indiana University estimated that a 28 percent increase in wet coefficient of friction would decrease skidding accidents by 50 percent. An increase of this magnitude could be achieved, for the vehicles most likely to skid, by replacing bald tires with tires having at least a groove depth of 1.6 mm (2/32 in.). Minimum tread-depth laws already exist in about 35 states and many other countries. Such laws are being effectively enforced in Germany and the United Kingdom. During the conference, a representative from Virginia indicated that minimum tread-depth laws can be effectively enforced by a required vehicle-inspection program every 6 months.