Chapter 15: Repair and maintenance of unpaved roads

This chapter examines the problems and issues of unpaved roads, which in many countries form the major part of the highway network and are the only means of travel for wheeled vehicles. It draws widely on publications by the South African Department of Transport, especially TRH 20:1990, The Structural Design, Construction and Maintenance of Unpaved Roads (South African Department of Transport, 1990).

Unpaved roads may be earth tracks, earth roads or gravel roads (Figure 15.1). Earth tracks generally consist of parallel ruts separated by vegetation. They may well be impassable during wet weather (Figure 15.2).

Earth roads are those where there is no imported gravel but the material is cleared of vegetation and lightly compacted, generally by passing traffic. Often shaped by materials taken from the side drains, they are normally constructed by a road authority and are important to the economic and social development of the area.