Traffic Operations and Management

The Freeway Service Patrol (FSP) is an incident management program implemented by Caltrans, the California Highway Patrol and local partner agencies to quickly detect and assist disabled vehicles and reduce non-recurring congestion along the freeway during peak commute hours. The first FSP program was piloted in Los Angeles, and was later expanded to other regions by state legislation in 1991. As of June 2004, there were ten participating FSP Programs operating in California, deploying over 315 tow trucks and covering over 1,500 (center-line) miles of congested California freeways. The...

This report describes the first phase of an ongoing research project investigating the use of the Paramics traffic simulation model in freeway operation studies. Objectives of the research include: obtaining an in-depth knowledge of the Paramics model for freeway applications, developing and evaluating a calibration process assessing the model's ability to serve as a tool for evaluating freeway improvement strategies, and investigating various improvement strategies for the I-680 freeway in the San Francisco Bay Area. The report first describes the Paramics model and initial tests on...

Attica Tollway (Attiki Odos Motorway), the peripheral motorway of Athens metropolitan area, is the first road concession project in Greece. Attica Tollway provides safe and uninterrupted traffic flow conditions, saving more 270,000 person hours of delay per day with substantial savings in fuel consumption and air pollutant emissions. During the Athens 2004 Olympic Games, special traffic management plans were successfully implemented to ensure quick and safe access to the Olympic venues and to maintain a high level of service to all tollway users. The paper presents routine and emergency...

Several factors contribute to traffic congestion on highway facilities including adverse weather conditions. However, the extent of weather impacts on traffic flow and congestion delay on freeways is not fully known. This study analyzed an extensive set of historical traffic data from the state of California to gain a better understanding of the proportion of traffic delay that can be directly attributed to weather. A congestion estimation model was developed to estimate vehicle delays directly attributed to rain on 17 urban freeway corridors. It was found that delay due to rain ranged...