Directional skid resistance assessment of horizontal-curve pavements

Abstract

This research demonstrated through a field study that directional polishing effects of cornering traffic produced significant differential directional skid resistance. The pattern of differential directional skid resistance varied along a horizontal curve. In the front straight segment, the most severe polishing occurred in the traffic direction, while in the rear straight segment the most severe polishing was in the backward against-traffic direction. In the curve segment, the centrifugal forces generated from the cornering movements of vehicles caused the most significant polishing in the radial outward direction. Combined polishing effects in both the lateral and longitudinal directions were found in the front and rear transition segments. The test results showed that the current pavement design practice of considering skid resistance in the forward direction is unsatisfactory as it would over-estimate pavement resistance to skidding in the radial direction.