Making headway towards a better understanding of service frequency valuations : a study of how the relative valuation of train service frequency and in-vehicle time vary with traveller characteristics

On-going urbanization has led to greater distances between homes and workplaces and more long-distance commuting, increasing the need for efficient inter-urban transport infrastructure. For sustainability, trains are preferred to private cars. Two key variables affecting door-to-door train travel time are in-vehicle time (IVT) and headway ; however, there is often a trade-off between speed and frequency in a system. If different categories of travellers value IVT and headway differently, their proportions on a route should affect traffic planning. Optimal system design might differ between routes carrying many commuters and routes carrying mainly passengers on single private or business trips. Knowledge of differences in relative valuations of headway versus IVT should therefore affect railway system design. We investigate whether the relative values of headway versus IVT differ between inter- urban commuting by train and single inter-urban trips by train, whilst also examining differences between socioeconomic groups. Stated choice (SC) data from 580 Swedish respondents are used in estimation. Individuals actually commuting and individuals not commuting but imagining that they are when answering the SC questions are asked about their preferences for headway versus IVT. Commuters are estimated to value increased headway 19 percentage points more than do non-commuters. Young people (under age 21 years) value headway more than do older people while people with children value headway less than do the childless.