Drivers of Demand For Passenger Transport Worldwide
G de Jong, O van de Riet, RAND Europe, NL
Over the past decades passenger transport has grown rapidly and it is expected that it will continue to grow rapidly in the future. For example, Schafer and Victor (2000) estimate that between 1990 and 2050, passenger transport in industrialized regions will grow by a factor of three, and that there will be a nine-fold increase in developing regions.
The purpose of the investigation reported in the paper is to gain an understanding of what drives the demand for passenger transport around the world (what are the key drivers of passenger transport demand and how do they affect passenger transport demand?) and how these drivers can be influenced.
In order to answer the research questions, a three-fold approach was taken that consisted of a literature study, data analysis, and case studies of urban areas. The three parts of the approach complement each other. The outcomes of the literature study formed the foundation for the rest. The data analysis and the case studies were used to fill in missing pieces. The input to the literature study included research reports from all over the world. The data analysis consisted of statistical models estimated on data for 130 countries and 90 cities gathered from past research projects. There were thirteen case studies: five cases from the developed world, and eight cases from the developing world. There were more cases from the developing world because the developing world is poorly covered in literature.
Passenger transport demand was studied at the level of actual decision-making by the passengers. Passenger transport can be decomposed into several choices that travellers make. The number of kilometres travelled (for the moment without distinguishing by mode of transport) is the result of decisions on the number of tours as well as on the destinations of those tours. The split of this total over modes is determined by another choice of the travellers: mode choice, conditional on car ownership. The traveller also has to decide on the time-of-day period for each trip and the route through the network, choices that have a substantial effect on the level of congestion. A driver of transport demand that has a major impact on one of these five travel choices, may have a limited impact on other travel choices.
The drivers of passenger transport demand can be clustered into four groups ?Population characteristics (income, population, household size, age structure, education, labour participation, ethnicity); ?Spatial characteristics (population density, location of activities, integration with transport network); ?Economic structure (composition, communication patterns, time routines); ?Mode characteristics (availability of private and public modes, service characteristics, infrastructure and vehicle capacity, travel cost and time).
The most important determinant of passenger transport demand in total, and of kilometres by car in particular, is household disposable income. The availability of private modes (car ownership) is crucial as well, but its future development depends to a large extent on income growth. However, there is no fixed trajectory between income growth and total car kilometrage, because the other drivers of demand may vary from situation to situation and in combination also have a considerable impact on car kilometrage. The most important determinants of car kilometrage after taking into account income and car ownership growth are:
* Household size;
* Size and age composition of the population;
* Labour participation and level of education;
* Population density and other elements of the spatial structure;
* Travel time and cost and other mode characteristics (these also affect the distribution of traffic over time-of-day periods and routes).
Especially the latter two categories (spatial structure and mode characteristics) provide points of leverage for policy-making.
Contents of the paper The paper will identify the key driving forces behind passenger transport demand and their effects. For each driver we provide a short description, the range of effects of the driver on transport in various settings (for urban and interregional transport and developing and developed countries), explanations of differences in these effects across countries and cities, and a short discussion of whether or not these differences are likely to increase or decrease over time. A discussion of the possibilities and limitations of policy measures, based on the outcomes of the driver analysis, will be included in the paper as well.
Schafer, A. and D.G. Victor (2000); The future mobility of the world population; Transportation Research Part A, Vol. 34, pp. 171-205.
Association for European Transport