"You could have sat down with me and in five minutes I could have told you"

In this paper a study of a new road scheme is used as a starting point in a discussion of the extent to which methods based in operations research (multicriteria analysis) and in psychology (repertory grid techniques) might, in principle and in practice, be used to influence the economic evaluation of transport schemes and the social and political decisionmaking to which these formal analyses can be major inputs. It is concerned with how people's perceptions of road schemes are formed, the degree to which they differ from each other, the extent to which it is possible to quantify the differences, and the justification for formal recognition of such differences in processes of decisionmaking. Our findings suggest that a very complex series of factors come together to influence people's perceptions and hence their evaluations. To this extent at least, gaining a thorough understanding of how different people perceive a project is often not the waste of resources that the title quotation of this paper suggests.