Comprehensive Life-Cycle Cost Analysis for Selection of Stabilization Alternatives for Better Performance of Low-Volume Roads

Abstract

Low-volume roads (LVRs), such as rural, farm-to-market, and less-used local and city roads, are an important part of the world's transportation infrastructure. LVRs have been credited as a direct cause of the socioeconomic development of rural communities. It has been estimated that 60% of the road network in the United States is made up of low-volume roads. The construction, maintenance, and rehabilitation of these roads are major tasks that result in about 54% of the total annual expenditure of transportation agencies in the United States. Better design and construction methods will lead to lower maintenance and rehabilitation costs of LVRs. Stabilization of weak subgrade soils to support LVRs is a widely accepted method of improving their performance. However, the selection of a stabilization alternative on the basis of cost–benefit analysis is a crucial task for a transportation agency and one that has not been addressed in a systematic manner. In this paper, a new conceptual engineering economics tool–based life-cycle cost analysis (LCCA) is developed to optimize and to select the best stabilizer and the stabilization technique for a given subgrade soil and given traffic conditions. In this analysis, agency, user, and externality costs are addressed. Two case studies are analyzed for European and U.S. road conditions to validate the LCCA model. Results demonstrate that, under specific boundary conditions, soil stabilization can play an important role, merging the environmental and mechanical effectiveness of low-volume roads.