Strategies for Winter Highway Maintenance
With the annual appearance of winter in northern states, come a host of transportation problems that carry severe costs to society. These costs impact in four major ways.
1.) Roads covered with ice or snow are slippery and inherently less safe for driving. Safety concerns provide a major stimulus to improvements in winter maintenance methods.
2.) The most common method of dealing with ice and snow on the roads is to apply salt (sodium chloride, generally in the form of rock salt) as a deicing chemical. Sodium chloride lowers the freezing point of ice and snow, so that it melts at a lower temperature. While there is at present no financially feasible alternative to salt as a deicing chemical (Transportation Research Board 1992), its continued use at present levels carries costs that must be addressed (damage to pavement and vehicles). How these issues are addressed will also drive changes in winter maintenance methods.
3.) As U.S. industry strives to maintain competitiveness in the global economy, techniques such as "just-in-time" manufacturing are becoming more prevalent. These techniques require that transit times (from supplier to assembler) be predictable and regular, but do not necessarily require that they be as short as possible (see Forkenbrock et al. 1993). Winter storms must be handled efficiently with respect to their effects on major routes; states that pay attention to such details will derive longterm economic benefits from such attention.
4.) The current trend toward reducing government spending at all levels (federal, state, county and municipality). Because winter maintenance is such a costly activity, it may be a tempting target for budget cuts. If winter maintenance budgets are reduced, those charged with managing winter highway maintenance operations will be required to do more (or at least maintain current levels of service) with fewer resources.
Considered together, these forces make this a highly appropriate time to study new methods of tackling ice and snow on highways. A major goal of this study is to determine which new technologies have potential to be useful and effective in winter highway maintenance, and to indicate strategies for the development, incorporation and deployment of new technologies into current methods of winter maintenance. In this report, we review the current state of practice and present the results of surveys that explore the needs of state departments of transportation (DOTs) as well as counties and large cities in Iowa. On this basis, several promising approaches and directions are recommended in Chapter 6, the strategy section of this report.