Traffic congestion in urban road and freeway networks leads to a strong degradation of the network infrastructure and accordingly reduced throughput which can be countered via suitable control measures and strategies. A concise overview of proposed and implemented control strategies is provided for three areas: urban road networks, freeway networks and route guidance. The paper concludes with a...

Connected autonomous vehicles (CAV) technologies are about to be in the market in the near future. This requires transportation facilities ready to operate in a mixed traffic environment where a portion of vehicles are CAVs and the remaining are manual vehicles. Since CAVs are able to run with less spacing and headway compared with manual vehicles or mixed traffic, allocating a number of freewa...

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 ...

This paper illustrates the macroscopic modeling and simulation of Interstate 80 Eastbound Freeway in the Bay Area. Traffic flow and occupancy data from loop detectors are used for calibrating the model and specifying the inputs to the simulation. The freeway is calibrated based on the Link-Node Cell Transmission Model and missing ramp flow data are estimated using an iterative learning-based im...

Loop detectors report traffic characteristics in real time. They are at the core of traffic control process. Intuitively, one would expect that as density of detection increases, so would the quality of estimates derived from detector data. However, as detector deployment increases, the associated operating and maintenance cost increases. Thus, traffic agencies often need to decide where to add...

BY XIAOYUE CATHY LIU, E.I.T., YINHAI WANG, PH.D., BASTIAN J. SCHROEDER, PH.D., AND NAGUI M. ROUPHAIL, PH.D. Introduction According to the 2011 Urban Mobility Report,1 roadway congestion cost a total of $101 billion and induced a total delay of 4.8 billion hours in the United States in 2010, with approximately 60 percent of the congestion occurring on freeways. Strategies have been implemented t...

This research involved an important extension of existing field-implemented and tested PATH research by the authors on individual vehicle reidentification, to develop methods for assessing freeway and arterial (and transit) system performance for the Caltrans PeMS (Performance Measurement System). PeMS has been adopted by Caltrans as the standard tool for assessing freeway system performance, b...

We present theory and evidence highlighting the disamenity effects of freeways on city centers and the structure of cities. In our model, disamenity effects from land use exclusion, negative externalities, or barriers between neighborhoods dominate access benefits in downtown neighborhoods compared with outlying areas, where access benefits are greater. These margins are especially relevant for...

Simulation of traffic flow is an effective tool for evaluating alternative roadway designs, particularly in congested urban areas. CORSIM, a traffic simulation model with detailed representation of vehicles and their interactions, was used to study the performance of two alternatives for a freeway reconstruction project in Oklahoma City. The simulation identified problem areas in the two freewa...