2020 Volume 6 Issue 2 Pages A_9-A_15
This study assumed that maneuverability such as car-following status illustrates an element related to driver perception, and investigated a performance measure capable of expressing the maneuverability as the quality of service of traffic flow (QOS). Follower percentage is such an index obtained by estimating the composite headway distribution consisting of follower and non-follower headway elements and is used as a performance measure that expresses car-following status. Analysis of pulse data obtained from vehicle detectors at multiple points on intercity expressways with different geometric structures and lane operations showed that follower percentage is influenced by lane traffic volume, vehicle pair, and lane operation. It is clarified that follower percentage can realistically express the behavioral characteristics of small and large vehicles, respectively, and probabilistically capture followers according to the actual traffic phenomenon. Thus, it can be concluded that follower percentage is a suitable index for evaluating the quality of service of traffic flow on intercity expressways under non-congested flow conditions.