Modeling of Freeway Traffic

Abstract

An integrated modeling of freeway traffic is developed, whose implementation in an uniform com- puter–aided simulation model facilitate comparative evaluation and systematic coupling of several traffic simulations, traffic controls, traffic measurements and traffic scenarios. The integrated mo- deling of freeway traffic is a basic mapping of freeway networks, control methods, measurements and different simulations of traffic flow. Commonly, the simulation of traffic flow bases on microscopic, macroscopic or mesoscopic traffic modeling. A microscopic modeling featuring descriptive rules is developed. A macroscopic mode- ling consisting of Navier–Stokes–like equations is considered. An integration of the microscopic modeling in any macroscopic modeling leads to a novel rule–based mesoscopic modeling. The three different modelings are numerically approximated by different numerical methods. In parti- cular, the finite element method can successfully be applied to the macroscopic modeling. The simulation programs evolved from implementations of numerical approximations of the three modelings are verified for usefulness in perturbation analysis and comparison of simulation results with detector data. Both the microscopic and the macroscopic simulation are able to reproduce typi- cal traffic phenomena like traffic jams or stop–and–go waves. Choosing a suitable velocity–distan- ce–relation the mesoscopic simulation proves a consistent link between microscopic and macros- copic simulations. The velocity–distance–relation respectively the velocity–density–relation are the decisive parameters of the shown simulations. Due to changes of these parameters, the simula- tion reacts very sensitively.