ABSTRACT
Transport models usually concern themselves with the equilibrium point - the intersection of supply and demand curves. It is already clear from the argument at the beginning of the chapter, that equilibrium can only be achieved either by continual iteration between distribution-modal choice and assignment submodels, or by setting up a large-scale joint distribution-modal choice-assignment mathematical programme. The essence of economic evaluation of alternative plans lies in the estimation of costs and benefits at the demand-supply equilibrium of each plan and, usually, the comparison of each with some base year; or possibly directly with each other. The point to be emphasised in the context of this discussion is that from any perspective, main model parameters are likely to be functions of supply-side variables computed at equilibrium, and a good deal of further research should be devoted to this issue. A plea is made not to forget the importance of ongoing research on land use-transport long-run equilibrium.
