Transport economists face many difficulties with both the theory and practice of evaluating travel time savings, even in developed countries. In less developed countries, most of these problems recur, but are compounded by poor data sources, different social and cultural values, and, frequently, inadequate resources to fund appraisals. After a brief discussion of the economic basis of conventional travel time saving valuation, this paper surveys the different practices adopted in less developed countries. It points to three major classes of road project (feeder roads, inter-urban road and urban schemes) and identified inconsistencies in the treatment of work and non-work travel time savings which, over and above any doubts about general questions of evaluation methodology, are likely to induce biases in project appraisal and selection. A series of recommendations is made for deeper analysis of travel time evaluation in the particular context of less developed countries. It is argued that the impetus for such work should come from the major funding organisations, and that, relative to the funds committed to investment in road projects, its costs should not be regarded as prohibitive. (A)
Samenvatting