Estimation of free-flow speeds on rutted asphalt two-way, two-lane roads with the soft shoulders

Abstract

Within the framework of research into the road condition assessment considering the utility values, the West Pomeranian University of Technology in Szczecin Dept of Roads, Bridges and Building Materials has made a number of spot-speed measurements in free traffic flow under adverse weather conditions and on variously rutted asphalt road surfaces. This paper presents the findings on the impact of the rut depths on the 85% speed quantile, v85. Furthermore, the average speeds for passenger vehicles, voav, and for goods vehicles, vcav reached at various available stopping sight distances, lz, are also presented herein.