Tire maintenance is a vital part of keeping a vehicle safe on roadways. Tires that have worn tread are more likely to have trouble gripping the road and are easily punctured. A tire that blows at high speeds can cause significant damage to the vehicle and possibly to other drivers. The U.S. Department of Transportation (DOT) has set regulations regarding tires and the legal wear of the tread. Georgia has taken these regulations further to define how accessories can be arranged near the tires' tread surface as well.
Over time the tread of a tire will wear away from traveling. According to the DOT, the tread of the tire must be at least 2/32 of an inch on any passenger type of vehicle to be considered legal. The legal tread depth for commercial vehicles such as buses, trucks or tractors, must be 4/32 of an inch or greater to be legal. The measurement of the tread is taken in a major tread groove of the tire and not at the edge of the tire where the tread is designed to flare down for water movement.
A vehicle will be considered unsafe in the state of Georgia if tire belts or body ply material can be observed through the tread of the tire or at the sidewall of the tire. Tread that is separating from the tire should be replaced immediately and not driven on Georgia roads. It is important to realize that tire belts can be exposed if the tire tread is cut or damaged by a road hazard. This means that the tread depth of the tire could measure appropriately but the tire is still in need of replacement.
Buses are not permitted to operate with re-grooved or retreaded tires under any circumstances on the front wheels of the vehicle. Re-grooved, retreaded or recapped tires are allowed on the rear wheels of buses, but the tread must still meet the minimum requirements of the tread depth as specified by the DOT. Load-bearing vehicles, such as tractors or trucks, are prohibited from using re-grooved or retreaded tires on the front wheels of the vehicle if the load weighs more than 4,920 lbs.
Commercial trucks, buses and semi-trailers are required to be equipped with mud flaps on the rear set of tires. These mud flaps must be installed in such a way so that they stop any rocks or road debris that is picked up by the tread of the tire. For commercial vehicles that have dual wheels on the rear axle, the mud flaps must be wide enough to cover the entire width of the tires.
