Analysis of Car-following Behavior on Sag and Curve Sections at Intercity Expressways with Driving Simulator

We analyzed the influence of road alignments such as sags and curves and the leading vehicle’s behavior on car-following behavior in a driving simulator experiment. Parameters of a car-following model were estimated from following-vehicle trajectory data collected for 37 participants. Then, relationships between the parameters and environmental factors were analyzed. The results showed that the parameters of the following-behavior model were significantly influenced by expressway alignments such as sags and curves, whereas differences in the leading vehicle’s behavior did not significantly affect the estimated parameters. These findings indicate that measures to assist the following vehicle’s acceleration and deceleration such as adaptive cruise control could be effective in preventing the breakdown of traffic flow.