Abstract

Induced travel has long been debated among transportation professionals and frequently ignored by planners when considering policy. (Induced travel refers to the observation that congested roads quickly gain new traffic after they have been expanded.) In fact, this has been observed since Western nations began to motorize and to construct major road facilities.1 Policy initiatives to implement more sustainable transportation systems frequently overlook the role that increased road capacity can play in undermining the objective of achieving greater sustainability. This chapter examines the theory and available evidence on induced travel effects and links this knowledge to policy considerations for achieving sustainable solutions, including the impact on oil dependence.