Over the past several decades Utah has experienced rapid population growth with nearly a 30% increase recorded between 1990 and 2000 alone. This has resulted in increased demand on Utah's existing interstate and arterial infrastructure. Recurring traffic congestion (i.e., AM /PM peak commute times) and non-recurring congestion (i.e., weather-related) result in an average annual cost of $250 million dollars to the traveling public. Recent Utah Dept of Transportation (UDOT) studies have confirmed that inclement weather plays a significant role in non-recurring congestion and associated negative impacts with respect to delays, mobility, productivity, and safety. It is important to note that one of the most cost effective solutions for mitigation of the congestion problem is driver habit modification.

In an effort to measure and potentially mitigate weather related traffic congestion a cooperative effort between federal (Salt Lake City National Weather Service), state (UDOT) and private sector (NorthWest Weathernet) entities is being undertaken. The project initiative is to develop mitigation strategies for non-recurring congestion associated with inclement weather. It is hoped that mitigation strategies can be developed which will influence driver behavior and, ultimately, reduce delays and congestion while at the same time minimizing accidents and the loss of productivity. A two-tiered approach will be utilized to reach this goal. The first tier is to create performance measures aimed at qualitatively assessing the effectiveness of road weather information provided to the traveler (i.e., National Weather Service products, UDOT's 511 and Commuterlink web reports). The second part of the approach is to monitor traffic patterns and driver behavior based on real-time and anticipated road and atmospheric conditions.

To assist in this endeavor the UDOT Traffic Mobility Section will monitor driver behavior utilizing a complex network of 240 Traffic Monitoring Stations (TMS) along Utah's urban freeway system. Performance measures will be developed to assess the impact of weather on traffic patterns as well as whether or not mitigation strategies have any influence on driver behavior during storm events. UDOT's Weather Operations Section will employ the use of 55 Road Weather Information Systems (RWIS) as well as, plow driver observations, road condition forecasts and Traffic Operations Center (TOC) Operator reports to monitor and track the impact of weather on area roadways.

It is hoped that increased awareness of the potential impact of pending weather events, through the use of enhanced wording in NWS products, UDOT 511 and CommuterLink web reports and targeted news releases, will result in subsequent driver modification. With a sufficient level of driver modification it is believed that it is possible to improve safety and reduce the costs associated with weather related congestion and associated delays.