Achieving sustainable mobility. Everyday and leisure-time travel in the EU

Erling Holden’s book Achieving sustainable mobility addresses the probably most demanding challenge facing European countries aiming to enter a course of sustainable development. Although sustainable mobility has been on the EU agenda for a decade and a half, progress towards this end has been modest. Based on a variety of multidisciplinary sources, including his own empirical research, Holden examines the merits of four main strategies to promote sustainable mobility: development of more efficient vehicles (based on conventional as well as alternative fuels); promotion of public transport; encouragement of environmental attitudes and awareness; and sustainable land-use planning. Holden evaluates these strategies against a number of hierarchically ordered sustainability characteristics, borrowed from the works of his colleague Karl Georg Høyer. Based on these criteria, Holden constructs a ‘sustainable mobility area’ where both a minimum level of available daily mobility of 11 km per capita and a maximum level of average daily transport energy use of 8 kWh per capita are met. Holden concludes that none of the four main strategies are by themselves able to ensure sustainable mobility. Therefore, they should be combined. Holden illustrates several such combinations, where different assumptions about attainable vehicle technology improvements imply more or less strong needs for limitations on the total volume of transport and shifts towards increased use of public transport. An important message is that even very optimistic levels of vehicle technology improvement will be insufficient to obtain sustainable mobility if transport volumes and the use of cars and airplanes continue to grow at present rates. The strength of the book is the careful discussion of the concept and key characteristics of sustainable mobility, and the interdisciplinary analysis of strategies to obtain this goal. However, the contributions to this analysis from the author’s own empirical research are less convincing. Holden’s data from Greater Oslo show, in line with a number of previous studies in European cities (including Oslo), that residents living close to the city centre travel shorter distances to reach daily destinations and carry out a higher proportion of their traveling distance by environmentally friendly modes. However, Holden also finds a correlation between high-density living and a high energy use for long-distance leisure travel by plane. He admits that this correlation does not necessarily imply any causal influence. When writing his ‘fourteen theses of sustainable mobility’ towards the end of the book, he still dismisses the compact city as a sustainable urban form, based mainly on the correlation between high-density living and energy use for flights. Instead, he recommends ‘decentralised concentration’ as the most sustainable pattern of development for cities above half a million inhabitants. According to Holden, residential development in such cities should mainly take place as medium-density development around suburban public Journal of Environmental Planning and Management Vol. 51, No. 3, May 2008, 471–475