AN INVESTIGATION OF VOLUME, SAFETY, AND VEHICLE SPEEDS DURING WINTER STORM EVENTS

Winter storm events can have a significant impact on mobility and safety. During the past year, these impacts have been investigated by the Center for Transportation Research and Education for the Iowa Department of Transportation. The project documented in this paper had two phases. First, data related to traffic flow, crashes, and weather/roadway conditions were collected from existing information management systems in Iowa. These data were then evaluated and analyzed. Second, a mobile video data collection system was used to collect data during seven winter storm events. The data collected and summarized into 15-minute increments included traffic volumes, vehicle speeds, vehicle gaps and headways, visibility (greater or less than 1/4-mile) and roadway snowcover conditions. This paper summarizes the results from both phases of this project.