Abstract
In the travel-demand sector, where time and cost frequently have a dominating influence on the attractiveness of a given journey, VTTS (value of travel-time savings) is most usually used to denote the monetary rate at which a given travel-time saving or loss in a particular context can be compensated for by a corresponding loss or saving of money. The purpose of this chapter is to give a short background to VTTS. The five sections in this chapter deal with: (1) conceptual models of time-cost trading; (2) experimental data; (3) the history of measurement; (4) current findings; and (5) observations and conclusions, including current research directions.