The empirical case studies in the book are synthesized into fourteen theses of sustainable mobility. These theses, which are related to the most important characteristics of sustainable mobility, are described in relation to the roles of the following: new conventional and alternative technologies, public transport, green attitudes, and land-use planning.
The theses are related to various ways of (i) halving per capita energy consumption for transport, (ii) ensuring access to appropriate transport, and (iii) equitable distribution in space and time of the positive and negative impacts of transport activities – which I consider as the three main characteristics of sustainable mobility. The relevance of the theses is not limited to EU policy; many of them apply to developed non-European countries and moreover, to developing countries. However, due to differences in socioeconomic and cultural contexts, care should be taken when applying them to non-European countries – particularly the theses that relate to the role of green attitudes.
Some of the fourteen theses are well known within the sustainable mobility literature but nevertheless can and should be backed by fresh empirical evidence. Others are not so well known, and some are even new, bringing new perspectives to the discussion of sustainable mobility, particularly the five theses that pertain to leisure-time travel. Taken together, the theses, well-known and new ones alike, constitute the basis for a theory of sustainable mobility.
THE ROLE OF CONVENTIONAL TECHNOLOGY
• Thesis 1: Growth in passenger transport mileage counteracts reductions in fuel consumption from increased engine efficiency.
• Thesis 2: Heavier, more powerful vehicles with energy-demanding auxiliaries are less fuel-efficient, which counteracts reductions in energy consumption from increased engine efficiency.
• Thesis 3: There is a significant gap between fuel consumption measured by official certification tests and actual on-road fuel consumption.
THE ROLE OF ALTERNATIVE TECHNOLOGY
• Thesis 4: The use of alternative fuels merely transfers energy consumption geographically (that is, from the vehicle to the production site and the distribution process); it does not reduce total energy consumption.
• Thesis 5: There are always trade-offs involved in the use of alterative fuels because their use merely changes environmental impacts thematically, rather than reducing the total overall environmental impacts.
THE ROLE OF PUBLIC TRANSPORT
• Thesis 6: Without strategies for reducing the total mileage for passenger transport by car and plane, the role of public transport as a means of reducing total energy consumption will be modest.
• Thesis 7: An affordable and well-functioning public transport system must ensure accessibility for low-mobility groups of people to their basic needs so as to prevent their social exclusion.
THE ROLE OF GREEN ATTITUDES
• Thesis 8: The correlation between specific (positive) attitudes towards everyday travel and everyday travel behaviour is significant, whereas the correlation between general (positive) environmental attitudes and everyday travel behaviour is insignificant.
• Thesis 9: People with green attitudes cast aside those attitudes in their leisure-time travel behaviour.
• Thesis 10: Membership in an environmental organisation does not ensure sustainable travel behaviour by members.
THE ROLE OF LAND-USE PLANNING
• Thesis 11: People living in high-density residential areas consume less energy for everyday travel than people living in low-density residential areas, but they consume more energy for leisure-time travel by plane than those people.
• Thesis 12: People having regular access to a private garden consume less energy for long-distance leisure-time travel by car and plane than people without such access.
• Thesis 13: People living in medium-density residential areas consume less energy for transport than people living in high- or low-density residential areas.
• Thesis 14: Decentralized concentration is a more sustainable urban form than the compact city, the dispersed city, and other alternatives.