This paper describes the development of long term rail demand forecasts which incorporate the influence of socio-demographic change on the demand for rail services. At the 2005 European Transport Conference we presented a paper describing an econometric analysis of aggregate rail ticket sales data to examine the effects on rail demand of changes to fare, timetable related service quality (time, frequency and interchange) and station accessibility. The focus of the work was on the specification of station catchment areas and the influence of socio-demographics on the demand for rail travel. The work used a range functional forms to examine how station access and egress times influence rail trip making propensity and concluded that statistically and theoretically superior models can be achieved using flexible inverted s-shaped distance decay functions. In this paper we apply the econometric model at a spatially detailed level to examine how forecast changes to population, employment, car ownership and household income might influence the demand for rail travel in the long term. Projections of each of these explanatory variables to the year 2031 were drawn from the UK Department for Transports planning data and mapped to station catchment areas. The forecast influence of socio-demographic change on the demand for rail travel in Britain shows: Population change is likely to increase the demand for rail travel by 6% across the country as a whole by 2031, with stronger growth for flows based in London and the South East (around 10% growth). Forecast changes to employment levels in the South East are likely to have a strong influence on rail demand increasing trips to London by over 9%, however on other flows the impact of employment is limited. With the exception of Central London, car ownership levels are forecast to increase with a reduction in the proportion of household without access to cars and a reduction in the demand for travel by rail. This impact is strongest for Non-London short distance flows and weakest (marginally positive) for London based flows. Overall the impact of changing levels of car ownership on rail demand is estimated to lead to a decrease of over 8%. Overall, the positive impacts of population and employment change are offset by the negative impacts of increased car ownership. At a flow category level however, non-London flows show a 10-15% reduction in rail demand due to socio-demographic change and London based flow a 10-15% increase in demand by 2031. The changes brought about by socio-demographic change are therefore estimated to be relatively small, especially when compared with the levels of growth to rail demand driven by relatively modest income growth. For the covering abstract see ITRD E137145.
Samenvatting