Accounting for user type and mode effects on the value of travel time savings in project appraisal: Opportunities and challenges

Differences in Value of Travel Time Savings (VTTS) between travel modes can play a decisive role in the ranking of projects that affect the travel time of different travel modes. Conceptually, between-mode differences in VTTS can be decomposed into the user type effect (UE) that accounts for differences in characteristics of user groups (e.g. income differences) and the mode effect (ME) that accounts for differences in travel modes (e.g. the comfort level). Several studies have disentangled and quantified these two effects. However, their potential use for project appraisal has not been thoroughly discussed in the literature.