Interviews From Four State DOTs Were Compiled to Develop Recommendations for the Implementation of Mobile Road Weather Information Sensors and Maintenance Decision Support Systems in Illinois.
Colorado, United States
Indiana, United States
Michigan, United States
Minnesota, United States
Evaluating the Benefits of Implementing Mobile Road Weather Information Sensors
Summary Information
Advancements in mobile road weather information sensing technology and cellular communications have led to the development of mobile Road Weather Information Sensors (RWIS) that can be installed on vehicles. The main goal of this study was to evaluate the benefits of implementing mobile RWIS in the state of Illinois to fill weather information gaps and aid maintenance operations. A literature review was conducted to gather and analyze latest data on mobile RWIS and its usage for collecting real-time winter roadway conditions to optimize winter roadway maintenance operations. Survey interviews were conducted across four state Departments of Transportation (DOT)s, namely Colorado, Indiana, Michigan and Minnesota to collect and analyze their experiences and best management practices for implementing and utilizing mobile RWIS and maintenance decision support systems (MDSS). The interviews covered various aspects of RWIS and MDSS usage such as deployment and usage, software and communication, encountered installation and operational challenges, required maintenance and data use, storage and retention.
- Use mobile RWIS and MDSS to reduce material usage and increase cost savings. CDOT reported that districts that used mobile RWIS reported an approximate 20 percent reduction in material usage, therefore they also requested for additional mobile RWIS units. Minnesota DOT reported that the use of mobile RWIS and MDSS in 11 winter events in 2010 enabled it to achieve an average of 53 percent reduction in salt usage and cost savings of $2,308,866. Michigan DOT stated that the forecast from MDSS enabled them to identify manpower for upcoming storms.
- Develop performance measures as per road-type to quantify the effectiveness of winter maintenance. All interviewed states reported that they utilized level of service classifications for their roadways that range from two to five levels with varying degrees of requirement for winter operations.
- MDOT specifies the performance measure for two levels of service classification (orange and blue routes) to be “pavement surface over its entire width be generally bare of ice and snow,” and “pavement surface be generally bare of ice and snow wide enough for one-wheel track in each direction.”
- MnDOT uses “bare-lane classification” as their performance measure, which states that “all driving lanes are free of snow and ice between the outer edges of the wheel paths and have less than 1 inch of accumulation on the center of the roadway.” Roadway classes are used to determine the allowable time to regain the bare lane. For example, super commuter roadways need to be cleared within 0 to 3 hours and secondary roadways are to be cleared between 9 to 36 hours.
- Consider the interest/support from DOT maintenance staff when selecting travel routes for vehicles with mobile RWIS. All four interviewed DOT personnel reported that interest/support from DOT maintenance staff was extremely important to the viability of mobile RWIS usage. Additional criteria used to select travel routes for vehicles equipped with mobile RWIS include high average daily traffic (ADT) roadways, problem areas, identified gaps of fixed RWIS sites, validation of data from fixed RWIS sites, and distribution equity among districts.
- Collected mobile RWIS data such as the level of friction and grip can be used as parameters to determine winter roadway treatment. CDOT recommended that friction coefficient estimates below 0.5 requires treatment; however, the threshold should be lower in metropolitan areas.
