Drivers’ Awareness of and Response to Two Significant Winter Storms Impacting a Metropolitan Area in the Intermountain West: Implications for Improving Traffic Flow in Inclement Weather

Abstract

Abstract Over the past several decades, Utah has experienced rapid population growth, resulting in increased demand on Utah’s existing interstate and arterial infrastructure. In the Salt Lake City, Utah, metropolitan area, recurring traffic congestion (i.e., peak commute times) and nonrecurring congestion (weather related) result in an estimated average annual cost of $449 million. Recent Utah Department of Transportation (UDOT) studies have confirmed that inclement weather plays a significant role in nonrecurring congestion and associated negative impacts. In an effort to measure and potentially mitigate weather-related traffic congestion, a cooperative research study between academic (University of Utah), state [Utah Department of Transportation (UDOT)], federal (National Weather Service), and private sector (Weathernet) entities was undertaken. Driver awareness surveys were conducted for two significant winter storms along the Wasatch Front urban corridor. Participants typically used media and personal sources for gathering weather and road information, with government sources (UDOT and NWS) used less frequently. Use of government and personal sources were significant predictors of behavior change. Satisfaction with all information sources was high. The most frequent commuting changes reported were route changes and shifts in travel schedule, especially leaving early to avoid the storm. Self-reported actions from interviewees were supported by measured changes in speed, flow, and travel time from the Performance Measurement System (PeMS) utilized by UDOT. The long-term goal is to use these results to provide insight into how the weather enterprise might more effectively communicate hazard information to the public in a manner that leads to improved response (change travel times, modes, etc.).