Ramp Closure Strategies for Incident Management (FHWA/TX-08/0-5422-1)

15. Supplementary Notes Project performed in cooperation with the Texas Department of Transportation and the Federal Highway Administration. 16. Abstract Non-recurring congestion accounts for a significant portion of freeway delay experienced by motorists in both rural and urban areas. Because access to these facilities is controlled by onramps, these can play a major role in minimizing the impact that unexpected incidents have on system performance. This project considered both methodological and practical considerations in using ramp closure as an incident management strategy. Novel methods for predicting incident severity were developed using probabilistic analysis, as well as a two-phase model for recommending which ramps should be closed, and for how long. These models were designed to be integrated with operations at a traffic management center, where responsibility for ramp closure is likely to be located. Further, an overview of closure devices is provided, along with their comparative advantages and disadvantages. 17.