Influence of Combined Highway Grade And Horizontal Alignment on Skidding

The purpose of the research reported here was to develop tentative guidelines for highway geometries and pavement surface characteristics to ensure adequate vehicle control during maneuvers on highway sections containing a combination of horizontal and vertical alignment. Accordingly, the objectives of the study were to (1) examine the factors that influence safe operations on highway sections having combined curvature and grade, (2) determine those operating conditions which define the onset of skidding, (3) evaluate by accident data analysis, simulation, and field studies, the factors involved in skidding , and (4) suggest measures for alleviating skidding accidents and recommend modifications to current AASHTO design polices.