Sustainable transport: analysis frameworks

For both passenger and freight transport, this paper presents analysis frameworks illustrating the interaction of factors that influence indicators of transport sustainability; identifies opportunities for policy intervention; and illustrates the possibility of unintended consequences of such intervention and the tradeoffs among the indicators. The frameworks account for systematic relationships, feedbacks, and rebound effects of making changes to the system. For passenger transport, physical, psychological, and social needs present themselves as primary influencers of sustainable transportation indicators. For freight, market forces and government policy are primary influencers of variables that are predominantly of an economic nature. Questions for future research are presented.