Development of Speed Prediction Models for Day-time Versus Night-time Conditions on Rural Multilane Egyptian Highways

Abstract

One of the shortcomings of the design speed concept is that it uses the design speed of the most restrictive geometric element as the design speed of the entire road. This may lead to potential inconsistencies among successive sections of a road. So, the operating speed-based method is popularly used for examining design consistency. Numerous studies have been completed on rural two-lane highways for predicting operating speeds. However, little is known for rural four-lane non-freeway highways. This thesis presents the development of operating speed models for day-time and night-time conditions for highways in Egypt based on a study of 58 horizontal curves at different sites on rural multilane roads. In each horizontal curve, Spot speeds were collected during the day and night at five points. Spot speeds were collected at the middle of first tangent, point of curve, middle of curve, point of tangent and the middle of second tangent.