Induced Travel Demand

An Evidence Review

Published in: for Transport (2018)

Posted on on November 28, 2018

by Fay Dunkerley, James Laird, Bryan Whittaker

Read More

Access further information on this document at

This article was published outside of RAND. The full text of the article can be found at the link above.

WSP and RAND Europe were commissioned by the Department for Transport (DfT) to undertake a literature review of the evidence on two key analytical questions that will inform the development of the second Road Investment Strategy 2 (RIS2) covering investment in the English strategic road network between 2020 and 2025.

  1. What does the evidence say on traffic growth trends? Will there be the demand for investment in new roads?
  2. What does the evidence say on induced demand? It was emphasised that the aim of this study is to review 'new' research/evidence and not to make recommendations about changes to modelling/appraisal methods. Further, the literature review should identify high quality literature and cover European and wider international evidence, as is relevant to the DfT.1.1.4.

The evidence from the literature review on induced demand is presented in this report. The implications of the evidence for economic appraisal of transport projects are also discussed. Evidence on traffic growth trends is presented in a separate report.

Research conducted by

This report is part of the RAND Corporation External publication series. Many RAND studies are published in peer-reviewed scholarly journals, as chapters in commercial books, or as documents published by other organizations.

Our mission to help improve policy and decisionmaking through research and analysis is enabled through our core values of quality and objectivity and our unwavering commitment to the highest level of integrity and ethical behavior. To help ensure our research and analysis are rigorous, objective, and nonpartisan, we subject our research publications to a robust and exacting quality-assurance process; avoid both the appearance and reality of financial and other conflicts of interest through staff training, project screening, and a policy of mandatory disclosure; and pursue transparency in our research engagements through our commitment to the open publication of our research findings and recommendations, disclosure of the source of funding of published research, and policies to ensure intellectual independence. For more information, visit

The RAND Corporation is a nonprofit institution that helps improve policy and decisionmaking through research and analysis. RAND's publications do not necessarily reflect the opinions of its research clients and sponsors.