The relationship of maintenance costs to terrain and climate on Interstate 40 in Tennessee

Terrain and climate are discussed as environmental factors affecting the maintenance costs of selected sections of Tennessee's Interstate Highway System. Among the environmental factors discussed are precipitation (distribution, frequency, and intensity), temperature (annual means, norms, and extremes), slope, local relief, soils, roadway gradient, geologic stability (landslide stability), and drainage. Precipitation, more than temperature, acts in conjunction with terrain to contribute to the spatial variability of maintenance costs. Heavy truck traffic is also discussed as a factor for high maintenance costs in Tennessee.

High maintenance cost segments of Interstate 40 are identified along the eastern escarpment of the Cumberland Plateau, in the hilly terrain of the western Highland Rim near the Tennessee River, and in the steep and geologically complex terrain along the Pigeon River in the Great Smoky Mountains.

While generalized relationships between maintenance costs and environmental factors are difficult to establish on a statewide basis, detailed analysis of specific high-cost segments of Interstate 40 suggests clear relationships between microenvironmental factors and costs.

This study suggests that maintenance costs are influenced by environmental factors related to the highway's location in areas of varying terrain and climate. Highway planners should consider environmental factors, not only as they affect the initial construction and operating costs, but also as they may contribute to long-term maintenance costs.