A great amount of engineering and development work is under way at the present time on the important subject of tire traction, especially under wet surface conditions.Typical facilities used in the industry for traction testing of tires are described.Tests to date have shown that by far the most important variables affecting tire traction are: 1. Speed. 2. The road surface. 3. Weather conditions as they affect the road surface (wet, dry, icy). 4. The conditions of the tire, particularly whether it is new or worn to the tread wear indicators.By comparing test tires with production tires with known traction qualities, tire manufacturers produce tires which perform satisfactorily for wet traction. However, owing to the many variables which affect tire traction, and owing to wide deviations in the test data, the conclusion is reached that the state-of-the-art today for measuring traction does not warrant the recognition of a tire traction performance level which can be defined in specific terms.