Rural Highway Design Consistency Evaluation Model

Design consistency assessment is a tool employed by designers to improve road safety. This study illustrates an investigation on two-lane rural roads in the Southern Italy without spiral horizontal transition curves to check a prediction consistency model. Two consistency measures were compared with the results in the scientific literature: the first was the area bounded by the speed profile and the average weighted speed; the second was the standard deviation of operating speeds for each segment. Combining these two measures by sensitivity analysis, a consistency model was developed by using results of a 2011 research project performing V85 prediction models.