Passenger mobility has been increasing in all regions around the world, and forecasts suggest this is to continue. Simultaneously there has been a perceptible shift towards faster modes of transport, which is also likely to persist. Projections suggest that by 2050, travel by aircraft and other high-speed modes could account for up to 70% of all passenger mobility in the industrialised world. Using two approaches, this study has looked for evidence of such shifts towards faster modes using historical travel surveys from the US.
The results of the empirical study suggest that in the US over the period 1983-2001, air travel has been increasingly used at shorter distances, both absolutely and relative to the use of personal vehicles. The distance at which air travel was favoured over personal vehicle travel was observed to decline from around 900 miles (1,450 km) in 1983 to around 680 miles (1,100 km) in 2001. This trend supports the plausibility of very high high-speed mode shares in 2050. The underlying causes are explored in an effort to contextualise these results.
Potential future impacts on the urban economy, society and lifestyles, and the environment, are discussed in light of findings from the empirical study. The potential detrimental impact on GHG emissions from increased use of air travel for shorter trips is identified, as is the evolution of urban form and the consequences for society that may result from a growing importance of air travel.
It is revealed that many of these impacts arising from greater air travel are interconnected and may be conflicting. For instance, a growing importance of airports as urban centres may be tempered by growing local environmental impacts of aviation. The interconnections are presented diagrammatically so that all are taken into account concomitantly, as required by the principles of sustainable development.