Optimizing Rural Road Conservation Expenditures

Abstract

A methodology of optimizing expenditures for rural road maintenance and rehabilitation is presented. The optimum schedule for pavement overlay and rehabilitation is determined, resulting in minimal costs during the road's economic horizon. In developing countries, the economic horizon usually varies between 10 and 20 years; in Ecuador, it was established at 17 years. During this period most of the road's socioeconomic benefits are obtained. The economic residual value is small relative to other transportation expenditures. Total expenditures during the service lifetime include construction, maintenance, pavement overlay or rehabilitation, and vehicle‐operating costs. The methodology was used in the evaluation of 2,700 km of rural roads in the Ecuadoran province of Chimborazo. The analysis shows that total expenditures will be the least when adequate, timely maintenance is implemented. Due to budget and other administrative limitations, maintenance cannot always be carried out as needed. In such cases, a precise schedule of pavement overlay or rehabilitation should be followed to ensure that total expenditures during the road's service lifetime are minimal. An optimal programming methodology is presented for pavement overlay as a function of road type, traffic volume, type of terrain, and maintenance level. The conclusions were found to be practical and economical for arid, subtropical, and tropical zones.