Effets externes et avantages sociaux du transport routier de marchandises : quelques remarques au sujet de l'étude financée par l'IRU

External effects and social benefits of road freight transports: a few remarks on the IRU-sponsored study. – The study conducted by a European team of researchers on behalf of the International Road Union (IRU) under the direction of Professor G Aberlé prompts a number of reservations, in particular as concerns the evaluation of the social benefits of long-distance road freight transport. The method used to arrive at this evaluation is that of "monetary economies". This measures the additional costs and losses in social usefulness that would result from a 100% or 30% transfer of long-distance road traffic to rail.Second thoughts on this evaluation give reason to doubt the assumptions on which it is based. The transfer scenarios are unrealistic. The definition of long distance is an inappropriate one. The assumption that prices correctly reflect costs is dubious. And, more generally, the assumption that "other things remain equal" implies the further assumptions that the road and rail transport production functions themselves would remain unaffected by the transfer ; that costs are independent of traffic level ; that the production and distribution system (organization in space, logistic chain management) would remain unchanged, and so on. Moreover, the analytical balance computed in the report seems to be of little significance compared with the economic calculations, and the evaluation makes no claim to any scientific standing as regards optimization theories.----------------------------------------------With the author and the publisher of the copyright agreement. The present version in PDF is under the copyright of EDITECOM (http://www.editecom.com/) - 1994.