Transportation agencies, which are responsible for providing safe, reliable highways throughout the winter season, face significant challenges:

• Travelers and commercial carriers with demanding delivery schedules expect higher levels of service.
• Transportation agencies have limited funding and staff.
• Reliable site- and time-specific reports of road conditions can be hard to get.
• Some weather conditions—particularly fog, frost, and blowing snow—can be difficult to forecast.
• Capabilities and limitations of new and innovative maintenance treatments are not fully understood.
• Agencies are losing their most seasoned maintenance workers, who have experienced diverse weather and treated a lot of roads during their careers.
• Transportation agencies face environmental challenges to the types and amounts of deicing materials they apply.

During the period of 2002–2012, a multi-state pooled fund study led by the South Dakota Department of Transportation developed and extensively deployed a Maintenance Decision Support System (MDSS). The work is directed by a Technical Panel representing every participating state and the Federal Highway Administration and is administered by the South Dakota Department of Transportation’s Office of Research.

Major MDSS components include:

• A vendor supplied and operated information system that assimilates a wide variety of weather and maintenance data and models pavement surface response to weather, already applied maintenance treatments, and feasible future treatments.
• A desktop graphical user interface customized to individual users, providing detailed information on weather and road surface conditions and predictions, as well as maintenance treatment recommendations.
• On-vehicle systems data systems that inform the MDSS of weather conditions, road conditions, and applied maintenance treatments and then inform equipment operators of predicted conditions and maintenance recommendations.

MDSS incorporates the scientific framework and computational tools necessary to reliably recommend sound winter maintenance treatment strategies.

RESULTS

Independent analysis of the benefits and costs of MDSS demonstrates potential for significant cost savings, improved service, or a combination of the two.

Indiana’s statewide deployment of MDSS during the winter of 2008-2009 provides the most direct evidence of MDSS benefit. Using MDSS as a management tool, Indiana reduced salt costs by $12 million and realized more than $1M savings in fuel and overtime. Even after normalizing for winter conditions, Indiana estimated overall savings at $11 million, 27 percent of its normal total winter budget.
In addition to cost efficiency, MDSS users have realized other intangible but important benefits:

• "One-stop" convenience for complete winter weather information.
• Better anticipation of storm events and resulting road conditions.
• Delivery of weather forecasts and maintenance recommendations directly to snowplow operators.
• More consistent and seamless winter maintenance among maintenance units.
• Reduced environmental exposure to deicing chemicals.
• Use of the MDSS storm playback feature as a powerful maintenance training and analysis tool.

A case study of New Hampshire's five previous winters showed that, had MDSS been used, 23 percent less salt could have provided the same level of service; alternatively, the incidence of "unacceptable" driving conditions could have been reduced by 10-15 percent with equal salt use. In either case, the overall benefit/cost ratio was about 8:1. Similar case studies in Minnesota and Colorado showed smaller, but worthwhile, benefit/cost ratios.

The full report, finalized in June 2012, assesses many strategies for Road Weather Management. These strategies improve safety, efficiency, and mobility. These findings along with the benefits and costs provide a valuable resource to those considering the implementation of Road Weather Management systems.