North Dakota Gravel Road Management: Alternative Strategies

Abstract

Gravel roads account for a large portion of the total 5.1 million km (3.2 million mi) of rural roads in the United States. These roads support the movement of farm families, rural residents, school buses, mail carriers, tourists, and agricultural commodities. In recent years, these roads have been affected by several trends. First, agricultural states are experiencing population shifts from farming areas to urbanized centers as farm sizes continue to grow, further reducing population densities and traffic levels. Second, some states such as North Dakota are experiencing a shortage in quality gravel supplies. Third, more rural road users perceive a lower level of service on gravel roads and demand better services, specifically more paved roads. Finally, the reduction in transportation budgets limits the number of gravel road kilometers that can be properly maintained. Several research efforts that examined alternative approaches to reduce gravel road maintenance costs are summarized here. These strategies may generally be classified into ( a) modifying gravel road surface for high traffic roads (i.e., paving or using chemical additives), ( b) reducing maintenance on gravel roads with lower traffic volumes, and ( c) closing unneeded gravel roads. These options require careful economic and legal analysis before they would be implemented. The results of a case study that investigated the feasibility of paving gravel roads with various traffic levels and a brief overview of a survey of chemical soil additives in Colorado, Montana, North Dakota, South Dakota, Utah, and Wyoming are reported.