Philosophy of road assessment in Australia - the changing needs of a developing road system

With only a slight oversimplification, one might contrast the traditional bottom up approach to estimates of road funding needs with the top down approach required by present circumstances. During the growth phase of the road system it was appropriate, or at least acceptable, to determine the total road budget from the bottom up by summing the costs of projects needed to achieve technically specified standards. However, as the road system approaches maturity, it loses its special status and has to compete for funds with other needs of society. Road funds are then determined largely by outside constraints and road programs need to be designed from the top down to fit within a limited budget. Maintenance of the existing road system absorbs an increasing share of the budget and the case for the decreasing component of discretionary expenditure is more and more determined by political considerations. The important lesson for the analyst or technical advisor is that technically determined unique solutions to road planning and budgetary problems may not be appropriate. They may even be counterproductive if they conflict with strong political pressures and are not amenable to adjustment and iteration to take account of these pressures.