An Approach to Prioritisation of Alternatives in Road Projects

Selection among alternatives is often a requirement in feasibility/planning stages of a road project. Prioritisation, using ranking tools, is then resorted to. While there are many multi-criteria decision analysis (MCDA) methods to carry out such prioritisation, compensatory methods for MCDA allow trade-offs between criteria, where a poor result in one criterion can be negated by a good result in another criterion. This provides a more realistic form of modeling than non-compensatory methods which include or exclude alternative solutions based on hard cutoffs. The weighted sum approach (WSA, a simple, but non-compensatory method) and technique for order of preference by similarity to ideal solution (TOPSIS, a compensatory method), finds prominence in their application to prioritisation of alternatives in road projects. As the rankings often vary, it is often deemed necessary to find the rankings using a third alternative method. This paper explores the use of another compensatory method, but one that does not find much application in prioritization for road projects, the concordance-discordance analysis (CDA) and compares the ranking results obtained from different methods for a hypothetical case of route selection that decision makers face during the feasibility stage of a road-project preparation.