Transport Planning and Environmental Assessment: Implications of Induced Travel Effects

Abstract

ABSTRACT This paper reviews recent changes to transport policy within the context of changes from policies of “predict and provide” to an integrated transport policy and the role of new knowledge on induced travel effects. The focus is on UK transport policy, but the implications are discussed in terms of overall relevance to transport policy in other countries. The discussion hinges around how new assessment procedures, including the move toward strategic environmental assessment, are linked to behavioral effects associated with induced travel demand. The linkage of the congestion-reduction objectives of transport policy and the political implications of how behavioral reactions can undermine those objectives via induced travel effects and changes in relative accessibility are discussed. Linkages to changes in accessibility and economic effects as described by simple urban economic theory are also discussed with a focus on the implications for transport policy. A review of new assessment procedures in the United Kingdom as implemented in recent years is then critiqued in light of this discussion. The focus is on whether changes to assessment procedures have led to improvements in decision making, especially from an environmental perspective as well as from stated government policy goals. Concluding comments focus on the inherently political nature of this process and the role that theory can provide in revealing these issues and providing more transparency to the links between stated objectives of policy and likely outcomes.