Induced demand is a phenomenon in transportation planning where increasing road capacity actually leads to more traffic rather than reducing congestion. This counterintuitive effect occurs because new or expanded roads make driving more attractive, encouraging people to take trips they otherwise wouldn't, switch from other modes of transportation, or move farther from their destinations.
The concept challenges the conventional wisdom that building more highways is the solution to traffic problems. As documented in the articles and resources below, the science consistently shows that expanding roadways generates additional traffic demand that fills the new capacity, often within a few years. This pattern has been observed across cities worldwide and represents a fundamental challenge for transportation policy.
Understanding induced demand is crucial for developing effective transportation solutions that prioritize sustainable alternatives like public transit, cycling infrastructure, and mixed-use development rather than endless highway expansion.
What's Up With That: Building Bigger Roads Actually Makes Traffic Worse
via @adamspacemann https://www.wired.com/2014/06/wuwt-traffic-induced-demand/
The Science Is Clear: More Highways Equals More Traffic. Why Are DOTs Still Ignoring It?
via @schmangee https://usa.streetsblog.org/2017/06/21/the-science-is-clear-more-highways-equals-more-traffic-why-are-dots-still-ignoring-it/
The Broken Algorithm That Poisoned American Transportation
via @A_W_Gordon https://www.vice.com/en/article/v7gxy9/the-broken-algorithm-that-poisoned-american-transportation-v27n3
Do more roads really mean less congestion for commuters?
https://theconversation.com/do-more-roads-really-mean-less-congestion-for-commuters-39508
What a 160-year-old theory about coal predicts about our self-driving future
https://www.theverge.com/2024/9/2/24232386/self-driving-car-jevons-paradox-robotaxi-waymo-cruise