Operating Speed Models on Horizontal Curves for Two-lane Highways

A variety of physical factors may influence speeds on two-lane highways. In the present study, the highway alignment of Shillong bypass is critically reviewed at several curved section to understand their speed characteristics. The purpose of this paper is to develop curve-speed prediction equations using data collected at 10 horizontal curves of the highway. It was found that the radius of curvature, sight distance and deviation angle had significant relation to the operating speed. Three equations were developed and the radius of curvature had the maximum impact on the operating speed at the circular portion of the horizontal curve, whereas the sight distance and the deviation angle had maximum impact on the operating speed at the entry of the curve.