A policy for sustainability of low volume traffic roads in an Australian context

Low volume traffic (LVT) roads make up the vast bulk of the Australian road network. The network ranges from tracks joining farms to sealed roads linking the major country centres. The problem for a country, which has a vast geographical area with a relatively small population, is to maintain this system of roads with the minimum practical investment, in a sustainable manner. The unusual circumstances of the Australian environment of the driest continent on earth, a geologically old continent and a weather pattern that regularly produces prolonged drought and periods of heavy rainfall in parts of the country, all impinge on the performance of pavements, influencing their lifecycle. The deep weathering of the surface rocks has limited the availability of high quality gravels. The relative dryness of subgrades allows the use of marginal pavement materials, thinner pavements and thin non-structural seals. The depletion of the best sources of pavement materials since the First Fleet arrived from England in 1788 has caused problems for road construction. This has forced consideration of the use of lower quality materials and the incorporation of recycled materials in the construction of the elements that make up the road reserve. The outcome of the combination of circumstances is a road network that can be regarded as fragile, particularly under increasing traffic and axle load. This paper addresses the issues of pavement lifecycle management and resource conservation as approaches towards providing sustainable LVT roads, under the influence of these many factors.