Skip to Content
Streetsblog California home
Streetsblog California home
Log In
Damien Talks

DamienTalks 40 – Michael Manville on Automatic Road Widenings

It's been a while since we recorded a #DamienTalks specifically for the California website, but now we're back with a good one. In this week's edition, Damien Talks with Michael Manville, a professor and researcher at UCLA.

#DamienTalks

Manville has hit a bit of Livable Streets fame with an article he wrote for the Journal of Transportation and Land Use. In that article, he outlines why laws requiring developers to invest in road widening to "mitigate" traffic created by their development don't actually do anything to improve traffic flow locally or regionally.

Almost nobody who understands transportation planning believes that these requirements do anything to improve traffic flow--yet these laws persist.

Manville doesn't only debunk the theory behind the laws, but also offers a solution...should policy makers heed his call.

You can read "Automatic street widening: Evidence from a highway dedication law" at the Journal of Transportation and Land Use here, and a summary of the article from Streetsblog USA here.

We’re always looking for sponsors, show ideas, and feedback. You can contact me at damien@streetsblog.org, at twitter @damientypes, online at Streetsblog California or on Facebook at StreetsblogCA.

Stay in touch

Sign up for our free newsletter

More from Streetsblog California

Eyes on the Street: Caltrans Protected Bikeway Near SD Freeway

Caltrans is the white hat. It's San Diego that messed up.

March 27, 2026

The Week in Short Videos

CTC Loves Highways, Streets for All Loves High-Speed Rail, and Streetsblog Loves Long Beach!

Friday’s Headlines

Sales taxes, rail extensions, bike lanes, and more...

March 27, 2026

Friday Video: Five Bike Advocacy Mistakes You Don’t Even Know You’re Making

For one thing, make sure that political leaders who say "no" to livable streets experience consequences for their decisions.

March 26, 2026

Metro Board Unanimously Advances K Line North Light Rail Extension

Mayor Bass backed off of her push for indefinite delays requested by some mid-city residents opposed to tunneling under their homes.

March 26, 2026

Transit Agencies Mark Progress as Ballot Efforts Intensify

Help gather signatures for the funding measures during this weekend's demonstrations.

March 26, 2026
See all posts