The California Freeway Performance Measurement System stores real-time data from 26,000 loop detectors. PeMS is accessed via an internet browser (http://pems.eecs.berkeley.edu/). It currently has 3 TB of data, growing at 2 GB/day. PeMS extracts useful information from these data and displays it in graphical or tabular form. These data provide an unparalled opportunity to assess freeway performa...

This paper aims to evaluate and compare the effects of different methods of ramp metering on the operational conditions of traffic flow at three levels: the network level (including the freeway and its connected ramps), the entrance ramp, and the upstream segment of the entrance. To achieve this aim, one of the most important urban freeways in the metropolis of Isfahan was selected. The traffic...

We develop a macroscopic model for mixed urban and freeway traffic networks that is particularly suited for control purposes. In particular, we use an extended version of the METANET traffic flow model to describe the evolution of the traffic flows in the freeway part of the network. For the urban network we propose a new model that is based on the Kashani model. Furthermore, we also describe t...

Methodologies for modeling ramp driver acceleration-deceleration and gap acceptance behavior during freeway merge maneuvers are presented. This study serves an important purpose by pointing to the limitations of current freeway merge models which treat the ramp driver acceleration-deceleration and gap acceptance behavior as deterministic phenomena. In addition, the interdependence of freeway me...

Tools for modeling and control of freeway networks by Ajith Muralidharan Doctor of Philosophy in Engineering Mechanical Engineering University of California, Berkeley Professor Roberto Horowitz, Chair This dissertation presents algorithmic tools that are useful to transportation engineers for freeway traffic modeling and control. A modeling framework that utilizes the link-node cell transmissio...

This paper is aimed at investigating the influence of different types of traffic flows on the capacity of freeway merge areas. Based on the classical gap-acceptance model, two calculating models were established specifically considering randomly arriving vehicles and individual difference in driving behaviours. Monte-Carlo simulation was implemented to reproduce the maximum traffic volume on th...

many studies have been conducted focusing on the effects of friction coefficient or texture depth on the highway accident risk. however, combined effects of these parameters have not been still addressed. in this research the interaction between friction coefficient, texture depth and accident rate in 30 freeway sections were examined. the accident data were gathered and an apparatus was design...

Transportation Research Record: Journal of the Transportation Research Board, No. 2278, Transportation Research Board of the National Academies, Washington, D.C., 2012, pp. 1–12. DOI: 10.3141/2278-01 Z. Z. Tian, Department of Civil and Environmental Engineering, University of Nevada, Reno, MS 0258, Reno, NV 89557. N. Wu, Institute for Traffic Engineering, Ruhr University Bochum, 44801 Bochum, G...

We develop an anticipative model-based predictive traffic control approach for ramp metering in freeway traffic networks. If ramp metering is implemented in a freeway network with alternative routes, traffic can spontaneously re-route due to the response of the drivers to the applied control actions. Although spontaneous re-routing can have a significant influence on the resulting traffic situa...

We investigate the stability of a nonlinear (piecewise linear and possibly discontinuous) model of a freeway onramp, controlled by two popular onramp metering schemes: Alinea and Percent-Occupancy. The freeway model is based on Daganzo’s cell-transmission model and can be understood as a hybrid system switching among several discrete-time linear dynamic equations. It is shown, under conditions ...