Abstract
A summary of friction performance data collected during NASA Langley Aircraft Landing Dynamics Facility track, diagonal-braked vehicle, and instrumented tire test vehicle evaluations using the ASTM E501 (rib tread) and E524 (blank tread) test tires is given. A varietyof pavement types, both grooved and ungrooved, and conditions are included. The principal factors influencing tire-pavement friction performance are discussed, and the advantages of using the blank-treadtire for wet pavement evaluations are identified. An indication of some future tire-pavement friction investigations is also given