Potential of Intelligent Transportation Systems in Mitigating Adverse Weather Impacts on Road Mobility: A Review

Adverse weather conditions for roads, which cause transportation systems to perform far below capacity, can severely affect society's economic output. As elimination of road weather events is not possible, transportation agencies perform proactive and reactive maintenance activities to minimize adverse impacts to keep roadways in optimum condition. While reactive maintenance activities are conducted to clear roadways after the occurrence of extreme weather events, proactive activities minimize these impacts beforehand. The success of proactive activities solely depends on the availability of accurate road weather information, however. Traditional road weather forecasting techniques rely on governmental weather services, which are not appropriate to predict route-specific road weather conditions. In this paper, the authors reviewed current intelligent transportation systems (ITS)-based solutions for minimizing road weather impacts and possible ITS innovations to incorporate diverse data sources to improve road weather management activities. ITS-based initiatives, such as road weather information system (RWIS), allow transportation agencies obtain accurate road weather assessments. Location-specific infrastructures such as RWIS are cost prohibitive for system-wide deployments. Connected vehicles equipped with weather sensors could enhance mobile road weather data collection. This strategy could improve proactive maintenance programs and reduce adverse effects of weather to the surface transportation system.

I. Impacts of Weather Events in Surface Transportation System

INCLEMENT road weather brings a twofold challenge to surface transportation systems: a reduction in traffic demand and roadway capacity and an increase in traffic crash risk [1]. The economic effects of road weather events are significant due to the reduction of overall surface transportation performance. Specifically, road weather events increase both travel time and crash risk, which results in a surface transportation system with compromised reliability [2]– [4]. To avoid these harsh consequences of bad road weather, travelers either cancel or reschedule discretionary trips, with subsequent negative impacts on regional economic activities [5], [6]. Crash frequencies increase significantly during inclement road weather conditions [7], although traffic demand is far lower than in normal conditions [6]. A study on the severity of inclement road weather related crashes during snowfalls found that cautious driving reduces crash severity, but not the frequency [7].