A multi-criteria methodology for optimising road investments

There is growing awareness that road investment appraisal, at both project and network levels, requires joint consideration of multiple criteria that relate to engineering, economic, social and environmental impacts. Several multi-criteria analytical methodologies exist for use at the project level. At the network level, strategies and works programmes need to be optimised under budget constraints by considering the set of relevant criteria. This paper presents a multi-criteria analysis methodology that can be used to optimise road network investments using the utility/cost ratio method. The multi-criteria analysis methodology is based upon the analytical hierarchy process technique, which systematically transforms the analysis of competing objectives into a series of simple comparisons between the constituent elements. The multi-criteria analysis methodology developed was applied to generate a work programme using a set of selected criteria to which relative weights of preference were assigned. The results obtained were compared with those of a similar work programme generated using conventional economic analysis in order to highlight the issue of effectiveness in road management and the use of multi-criteria analysis to solve a classical multi-objective optimisation problem under budget constraints.