Experienced travelers know that during inclement weather, they need to adjust their schedule to take delays and unreliable travel times into account. Some travelers will even defer trips to another time or cancel the trip. While the ordinary traveler evaluates travel options based on experience, it might be expected that transportation professional managing highway and transit systems would have something more analytical than experience to make decisions regarding traveler information, traffic management, and transportation system control. Unfortunately, traffic analysis and operational tools (simulations models) and standards for traffic performance (e.g., the Highway Capacity Manual 2000) assume clear conditions, and transportation managers are left with only their own experience to manage and control the transportation system when faced with inclement weather of varying intensities. This report describes the impacts of inclement weather identified through the literature and through prior research conducted by the Center for Transportation Research and Education (CTRE). The finds of recently completed research conducted to quantify the impact of weather on traffic flow are specifically highlighted. The most important conclusion of this research is that weather matters—weather conditions have an important impact on traffic safety, traffic demand, and traffic flow. Much more research is needed to measure, understand, and develop management strategies to mitigate inclement weather impacts. (Author/publisher)
Samenvatting