The valuation and demand impacts of the worthwhile use of travel time with specific reference to the digital revolution and endogeneity

The research reported here is concerned with how the worthwhile use of travel time might impact on the value of travel time savings (VTTS) and on demand set in the context of the rail travel market in Great Britain. It has long been recognised, in a variety of literature, that improvements in worthwhile activities which will have been delivered by the digital revolution will impact VTTS and demand yet there is surprisingly little reliable evidence and official appraisal practice does not accommodate any such effects. In a large survey of rail travellers, we have explored how activities while travelling impact on VTTS and demand. An important feature of the study was to account for endogeneity whereby variations in VTTS estimates according to the worthwhile use of time are biased if drawn from comparisons across individuals of what they do while travelling rather from comparing within individual variations in activities. Indeed, we clearly demonstrate the impact of not allowing for endogeneity and indicate its presence in other studies. We find that the VTTS does vary according to activities undertaken while travelling in a largely credible manner and is broadly consistent with behavioural responses to different available activities. The evidence supports the VTTS falling over time due to the digital revolution and rail demand increasing. These are modest rather than considerable changes but nonetheless contribute a better understanding of evidence relating to VTTS and rail demand variations over time