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25 CHAPTER SEVEN EMERGING TECHNOLOGIES There are several areas where emerging technologies hold responding agencies familiar with the MDSS believe it will promise for winter highway operations. These include a holis- develop into a useful tool. tic integration of weather forecasts, pavement conditions, and rules of practice in the form of a maintenance decision Key examples identified by the MDSS field testing that support system (MDSS). Other examples are the increasing are primed for improvement include better near-real-time deployment of fixed anti-icing spray systems, fog warning precipitation information, the value of route thermal map- systems, variable speed limits, and winter maintenance route ping in attempting greater accuracy at determining where and optimization. when to apply chemicals, and the importance of blowing snow prediction and treatment. STORM MANAGEMENT Fixed Anti-Icing Spray Systems FHWA Maintenance Decision Support System Fixed installations to apply anti-icing liquid are relatively A significant event during the period covered by this synthe- new, primarily occurring over the 10 years covered by this sis is the development of a prototype MDSS commissioned by synthesis. Several of the responding agencies have installed the FHWA Office of Transportation Operations. The pro- such systems on roadway sections and structures. Edmonton, totype was conceived in cooperation with stakeholder state Illinois, Maryland, Minnesota, and Washington State all have DOTs and operationally tested during the winter of 2002/2003 bridges with fixed spray systems, representing approximately on selected routes maintained by Iowa. The project goals 12 bridges or structures. Nebraska uses the technology on the were to develop a prototype that: approach to some bridges as well as a downgrade to a stop- light. Nevada is in the planning stages of incorporating spray Capitalizes on existing road and weather data sources; systems in new freeway construction. Augments data sources where they are weak or where improved accuracy could significantly improve the Lengths of roadway covered by the various installations decision-making task; vary from 150 ft to 3,500 ft, over two, three, and four lanes, Accomplishes data fusion to make an open, integrated, on two-, five-, and eight-lane roads. A majority of the instal- and understandable presentation of current environmen- lations use potassium acetate. Magnesium and calcium chlo- tal and road conditions; ride are also used, but to a lesser extent. Processes data to generate diagnostic and prognostic maps of road conditions along road corridors, with There are many ways in which the agencies have experi- emphasis on the 1- to 48-h horizon (historical informa- enced integrating these systems into their operations. For Cal- tion from the previous 48 h will also be available); trans, it has reduced the need for storm patrol on an isolated Provides a display capability on the state of the roadway; section of road. Less effort by trucks before and early in a Supplies a decision support tool, which provides recom- storm are benefits cited by Illinois and Maryland, two states mendations on road maintenance courses of action; and that both still spread salt on the structures if storms are in Provides all of the above on a single platform, with progress or intensifying. Both Maryland and Minnesota have simple and intuitive operating requirements, and does integrated some of their spray systems with an on-site RWIS so in a readily comprehensible display of results and ESS. For Maryland, this automation addresses frost control, recommended courses of action, together with antici- minor storms, and snow squalls. Minnesota, Nebraska, and pated consequences of action or inaction ("Project Washington State have systems that are manually controlled. Description" 2001). The city of Edmonton installed its system only recently, dur- ing the 2003 summer, and did not at the time of this synthe- Most agencies surveyed at least know that the FHWA sis have performance experience to share. Nevada cautioned MDSS exists. More than 40% report having had key involve- that conflicts are often encountered between bridge design- ment or participating at a stakeholder level. One-half of the ers and operations in installing the systems on structures.