The Department of Transportation requires each manufacturer to grade its tires under the Uniform Tire Quality Grade (UTQG) system which establishes ratings for treadwear, traction, and temperature resistance. It is important to note that these tests are conducted independently by each manufacturer and not by the Department of Transportation. The treadwear rating (440) refers to the durability of the tire, not necessarily the projected life of the tire. Since the test is conducted by each manufacturer, and the grade is assigned after the tire has only experienced a small amount of treadwear, there is room for interpretation. While it may be helpful to compare treadwear grades within the same manufacturer, it might not be as helpful to compare the grades across multiple brands or manufacturers. The traction rating (A) refers to the tire’s ability to stop in a straight line on wet asphalt and concrete under the controlled conditions of the test track. The test does not measure the tire’s cornering ability or hydroplaning resistance in wet conditions or braking and handling in dry conditions. The traction grades consist of AA, A, B or C, with AA being the highest. The temperature rating (A) refers to the tire’s resistance to the generation of heat when driven at high speeds. The grades range from A through C with A being the highest, making tires with an A grade most effective at dissipating heat.