Traffic models play an important role in both today’s traffic research and in many traffic applications such as traffic flow prediction, incident detection and traffic control. In this paper we concentrate on motorway traffic models for traffic control. First, we discuss why traffic control is important for both practice and research. We also argue why a model-based approach to traffic control ...

This paper addresses a novel idea of real-time traffic safety improvement on freeways. First by predicting traffic crashes on the freeway mainline using on-line loop detector data, then by proposing ITS remediation strategies to reduce the crash risk in real-time. The results of the predictive models were found to be consistent with the probable mechanisms of crashes under different flow regime...

The adjoint method provides a computationally efficient means of calculating the gradient for applications in constrained optimization. In this article, we consider a network of scalar conservation laws with general topology, whose behavior is modified by a set of control parameters in order to minimize a given objective function. After discretizing the corresponding partial differential equati...

Variable speed limit (VSL) control, combined with ramp metering, is one of the most efficient real time strategies to substantially improve traffic flow and reduce the congestion problem in road transportation systems. One way to design control strategies applicable in real time is to represent the vehicle flows with a hybrid dynamic model. Mixing flow models and discrete event approach, a batc...

Traffic flow on freeways is a nonlinear, many-particle phenomenon, with complex interactions between vehicles. This paper presents a stochastic model of freeway traffic at a time scale and of a level of detail suitable for on-line estimation, routing and ramp metering control. The freeway is considered as a network of interconnected components, corresponding to one-way road links consisting of ...

In this paper we first present an extension of the macroscopic traffic flow model METANET to multi-class flows. The resulting multi-class model takes into account the differences between, e.g., fast vehicles (cars) and slow vehicles (trucks) including their possibly different free-flow speeds and critical densities. Next, we show how this model can be used in a model-based predictive control ap...

The objective of this paper is to develop a realistic and operational macroscopic traffic flow simulation model which requires relatively less data collection efforts. Such a model should be capable of delineating the dynamics of traffic flow created by the merging and diverging activities and complex geometric conditions. In addition, it should have the capability of describing shock wave phen...

TECHNIQUES FOR EVALUATING THE PERFORMANCE OF PRE-TIMED RAMP METERS USING ARCHIVED ITS DATA Robert L. Bertini Civil & Environmental Engineering Portland State University P.O. Box 751 Portland, OR 97207-0751 Phone: 503-725-4249 Fax: 503-725-5950 Email: [email protected] Ahmed El-Geneidy Center for Urban Studies Portland State University P.O. Box 751 Portland, OR 97207-0751 Phone: 503-725-5946 Fax: ...