Research was conducted to discover and develop a means of network evaluation that will help to determine just who benefits or loses from a particular network change. A method of evaluation is described which makes it possible to compare networks even though the interzonal demand for travel over the two networks may differ. The method can be used to compute the net user benefit accruing from flows over a given network, but is most useful in comparing alternative networks on the basis of the difference in net user benefits accruing from them. It requires interzonal traffic volumes and interzonal separations from each alternative network. The effect of alternative networks on travel demand can be accounted for. Constant or fixed travel demand need not be assumed. The method is based on a consistent economic rationale. It uses consumer surplus as a measure of benefit. The measure of net value produced by the method is only as comprehensive as the data on which the values of interzonal separation are based. There is a need for more comprehensive measures of interzonal separation. Although only two networks may be compared at a time, two of the versions of the method require estimation of only a partial segment of the demand curve for travel from each zone. The version advocated for current use requires only the interzonal volumes and the interzonal separations for each network being evaluated. It is not constrained to traffic assignment, if reliable volume and separation data are available from some other source.
Abstract