ership rates are flatter), the third factor (especially ageing of the population) may reduce passenger-transport intensity - although this will be highly related to the second (urban spatial distribution) factor - and the availability of public transport alternatives. A summary of relevant passenger elasticities indicates that a range from 0.6 to 1.4 has been observed historically in industrialised countries, with a recent OECD average of 1.0. Against this is the possibility that Big 5/developing countries could experience higher passenger elasticities, perhaps in the 1.5-2.0 range experienced by industrialised countries in the earlier 1950-70s period. Table 4.8. Relevant passenger elasticity relationships Study Variable Elasticity 1. Road and Rail Passenger Landwehr-Marie-Lilleu (2002) OECD 1.0 - with range of 0.6 (North America) OECD (1986-97) to 1.4 (Western Europe) Tsamboulas (nd) EU accession countries Forecast of 1.0 (2000-20) WBCSD (2004) Global (2000-30) Forecast of 0.53 Landwehr-Marie-Lilleu (2002) Global Forecast of 0.43 (2000-30) 2. Road passenger Song et al. (1993) selected industrialised GDPpc Range from 1.1 to 2.3, with most estimates countries (1950-70s) in narrower range of 1.5-2.0 Johansson-Schipper (1997) Range from 0.7 to 1.3, with best-guess of 1.2 Information and Communications Technologies (ICT) A study of the impact of ICT on transport found that advanced vehicle technologies have the future potential for automated driving, which (along with improved road network management technologies) holds promise for increasing transport safety and capacity.43 There is no doubt that, over the 2000-30 period, continued vehicle and energy-efficiency technology improvements will shape transport energy use and driver behaviour. However, it is not expected that technology will fundamentally affect the growth of passenger transport (relative to the impacts of rising income, GDPpc and vehicle ownership). INFRASTRUCTURE TO 2030: TELECOM, LAND TRANSPORT, WATER AND ELECTRICITY - ISBN 92-64-02398-4 © OECD 2006 4.