Induced Travel Policy Brief

It is well established that adding roadway capacity generally increases network-wide vehicle miles traveled (VMT), a phenomenon commonly referred to as “induced travel.” Accurately estimating induced VMT is essential to accurately calculating the costs and benefits of roadway expansion projects, and determining how and how much to mitigate the project’s environmental impacts. However, travel demand models have historically failed to fully capture the induced travel effects of roadway expansion projects. The purpose of this project is to help inform USDOT on travel demand modeling practice by summarizing in an accessible policy brief the induced travel effect and the historical challenges of fully incorporating induced travel into travel demand modeling practice.