Operational Impact Curve for Transportation System Relating Precipitation Intensity and Flood Depth to Vehicle Speed

摘要

This paper describes impact of flood depth on the transportation system in Houston Texas. Generally, bad weather simultaneously impacts on derivers, by reducing visibility, and also the conditions of vehicles and roadways. These effects cause reduction speed and increasing density in roadways, so transportation agencies are seeking to integrate (or consider) flood, and whether in general, into traffic operation in order to improve system functionality. It should be mentioned the driver's behavior is very sensitive to the environment they derive in; for instance in flood situation, some drivers cancel their trip, some other choose another pathway, that is usually longer than normal one and these new decisions will effect on the transportation system indirectly. In this study, the methods that have been used to relate precipitation intensity and flood depth to reduction in speed, are reviewed. Then, considering a case study of Houston, because of the commonness of flood events in that area, flood depth-velocity reduction analyses will be conducted for Highways. The developed curve will be used to link the flood model to a transportation model, which considers the effect of runoff/flood on the transportation parameters. The paper will also report existing curves and techniques to represent operational impact (e.g., possibility, traffic flow volumes) on transportation system.