The historical development of equipment for constructing and maintaining the surface of earth and gravel roads is reviewed. The use of tractor-drawn graders and drags is emphasized. The case for tractor-based road maintenance operations for these roads in developing countries, instead of the normal motor grader and truck-based operations, is also developed. For many secondary and tertiary road networks, routine and some periodic maintenance could be carried out using wheeled agricultural tractors as the sole power units towing mechanical graders, gravel haulage trailers, water bowsers, and rollers, asrequired. The operations could be supported by local labor for suchactivities as gravel excavation, loading and unloading, spreading, and drainage maintenance. The road maintenance could be carried out by direct labor (force account) organizations or contracted out to the private sector. Contract agricultural work is already well established in many developing countries and road maintenance and improvement activities could extend the type of work carried out by tractor-owning contractors. Tractor-based road maintenance operations would be significantly cheaper in terms of capital and running costs. The logistic and support problems of such operations would also be less than for current motor grader-based operations. Tractor-based road maintenance operations would make more effective use of the limited financial and other resources available to road maintenance organizations in developing countries. This paper appears in transportation research record no. 1291, Fifth international conference on low-volume roads, may 19-23, 1991, raleigh, north carolina, volume 1.
Samenvatting