Aircraft tire and runway surface conditions can be crucial in meeting aircraft ground operational performance requirements, particularly under adverse weather conditions. Gaining a better understanding of the many factors influencing the tire/runway friction interface is the aim of several ongoing NASA Langley research programs which are described in this paper. Results from studies conducted at the Langley Aircraft Landing Dynamics Facility (ALDF) and tests with instrumented ground vehicles are summarized to indicate effects of different tire and runway properties. Several joint NASA/FAA/Industry programs are described together with current test plans. The scope of future NASA Langley research directed towards solving aircraft ground operational problems related to the tire/runway friction interface is given.