This paper validates the vehicle type-dependent car-following heterogeneity from micro- and macro-aspects by using Next Generation Simulation (NGSIM) trajectory data. Regarding the micro-viewpoint, traffic conflict analysis techniques and three surrogate safety indexes (i.e., time headway (TH), time to collision (TTC) and safety margin (SM)) are introduced to evaluate the safety performance during ‘steady’ car following. When driving or following a larger vehicle, Z-test results show that TH, TTC and SM all become higher significantly, that is, the driver’s accepted risk tends to be lower. From the macro-viewpoint, with the aggregated traffic data, a flexible Lagrangian fundamental diagram is calibrated by a bi-level optimization procedure. These calibrated curves illustrate that during close car following process with the same speed, the driver generally keeps a higher gap distance with the leader when following or driving a larger vehicle. Therefore, the consistent findings contribute to the conclusive results about the vehicle type-dependent car-following heterogeneity.
Empirical validation of vehicle type-dependent car-following heterogeneity from micro- and macro-viewpoints
Transportmetrica B: Transport Dynamics ; 7 , 1 ; 765-787
2019-12-23
23 pages
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
Online Contents | 1998
Online Contents | 1997
Online Contents | 1995
Online Contents | 1995
Online Contents | 1994