About the research
This study is part of a three-year research project funded by the Integrated Transport Commission to identify the factors most associated with those who travel long distances, their influence and strength. This information can then be used to produce a model to forecast the volume of long-distance travel by road, rail, coach and air.
The results show that there is a strong relationship between long-distance travel and income: air appears to be most income-elastic, followed by rail, car and finally coach. This is the case for most journey purposes and distance bands. Notable is the substantial difference in income elasticities in rail travel for business or commuting as opposed to leisure travel. Moreover, the income elasticity for coach travel is very low, and zero for the majority of purpose-distance bands, suggesting coach travel is a less preferred travel option in comparison to car, rail and air. In addition, longer-distance journeys appear to be more income-elastic than shorter journeys.
The study indicates that women travel less than men, the elderly less than younger people, employed travellers and students more than others, and those in households with children less than those without. Long-distance travel is also lowest for individuals living in London and greatest for those in the southwest; further, the number of travellers increases as the size of the municipality grows smaller.
Overall, the study indicates that economic growth remains the single biggest factor affecting long-distance travel demand in Britain, and notes that in the absence of major policy measures the demand for air travel would accelerate.
Methodology
An econometric regression model was used to identify the significant determinants for long-distance travel and to quantify their direction of causality and strengths in terms of elasticities. The estimated models express the distance travelled for long-distance journeys as a function of income, gender, age, employment status, household characteristics, area of residence, size of municipality, type of residence and length of time living in the area.
A time trend is also included to capture common changes in long-distance travel over time not included in the explanatory variables. Separate models are estimated for total travel, travel by each of four modes (car, rail, coach and air), travel by five purposes (business, commuting, leisure, holiday and visiting friends and relatives) and two journey lengths (less than 150 miles and 150 miles or more one way), as well as 35 mode-purpose-distance combinations.
Publications
This research work is published in the following journal:
Dargay, J.M. and Clark, S. (2012) ‘The determinants of long distance travel in Great Britain’, Transportation Research Part A: Policy and Practice, 46(3), pp. 576–587. doi: 10.1016/j.tra.2011.11.016