Induced travel demand: Evidence from a pseudo panel data based structural equations model

Induced traffic, defined as additional demand generated by improvements in travel conditions, has been a topic of research for many years. While previous studies have focused on specific and localised changes, the research described in this paper deals with the aggregate effects of changed generalised costs of travel on traffic generation: the propensity of participating in out-of-home activities on a given day, the number of trips and journeys conducted, and the resulting total times out-of-home and distances travelled. The generalised cost and accessibility elasticities estimated with a structural equations model for a pseudo panel constructed with the Swiss National Travel surveys since 1974 are surprisingly substantial even after correcting for age, cohort and other socio-demographic effects.