REVIEW OF STUDIES LEADING TO EXISTING VALUES OF TRAVEL TIME

This paper attempts to emphasize the most empirical contributions to the valuation of travel time under varying circumstances. Most of these studies estimated these values as by-products of single or simultaneous travel choice and demand models in which the emphasis is on prediction rather than on capturing the concept of the notion of the value of travel time. Most of the studies discussed have produced total sample values of travel time savings due largely to the inadequate sample sizes required for stratifications and have resulted in insignificant income-related values. However, the values do tend to show some semblance of consistency when converted to international units, but before improved (stratified) empirical estimates can be made, improvements to the procedures previously used to obtain estimates are required.