NAASRA ROADS STUDY: RURAL ARTERIAL ROADS REPORT

Changes to the inventory of the rural arterial road system in Australia over the ten year period 1981-1991, with expenditure on roads at each of four different levels, were predicted by the use of a computer model NIMPAC. The changes in the extent of the network in each of three categories, "good", "fair" and "poor" were predicted and used to arrive at conclusions regarding the various effects of the different funding levels. The levels evaluated were 75 per cent, 100 per cent, 125 per cent and 150 per cent of 1980/81 funding continued in real terms over the period 1981 to 1991. The road length on national highways in both the poor and fair categories is greatly reduced between 1981 and 1991 at all funding levels. However a substantial reduction, of approximately 200 kilometres, is obtained for each of the 25 per cent funding increments. The amount of travel in both the poor and fair categories increases between 1981 and 1991 at all funding levels. A funding level of 125 per cent of that of 1980/81 is required to reduce the proportion of travel in the poor category to the 1981 level. In terms of national highway width and surface type standards, 86 per cent was substandard in 1981, and at 1991 this is reduced to 56 per cent at the lowest funding level and to 18 per cent at the highest level. (TRRL)