The Two-Step Model of Operating Speed on Horizontal Curves Based on Driver's Information Collection and Processing

Based on the model of the driver's process of collecting and dealing with information of free-flow passenger cars on freeway, this article explores the factors and corresponding rules, which affected speed on a horizontal curve. A two-step model using the statistical method was developed for prediction of operating speed on horizontal curve with different joint alignments. Compared with the result of field data and the prediction of the Australia model, the two-step model has the merit of high prediction accuracy with the 85th-percentile operating speed. The model could be applied widely in the alignment design approach of operating speed and traffic simulation.