This four-part study is based upon tests planned and conducted by the SAE Tire Committee. The introductory remarks are written to give a brief outline of the complexity of tire traction measuring procedures and to describe the methods used in this work.The second part of the study deals with the methods used. Three basic methods were used, based upon stopping distance, vehicle deceleration, and towed skid trailers.In the third section, the results are analyzed. Test data from various types and sizes of tires are presented which show the effect of tire wear, vehicle speed, and various test surfaces.The study is finalized with conclusions and recommendations. Conclusions permit us to offer a basis for establishing minimum values expressed as related to a standard for straight ahead motion for passenger tire traction on wet pavement. Recommendations are offered for future activity.