For critics of widening projects, the prime example of induced demand is the Katy Freeway in Houston, one of the widest highways in the world with 26 lanes.
Immediately after Katy’s last expansion, in 2008, the project was hailed as a success. But within five years, peak hour travel times on the freeway were longer than before the expansion.
Matt Turner, an economics professor at Brown University and co-author of the 2009 study on congestion, said adding lanes is a fine solution if the goal is to get more cars on the road. But most highway expansion projects, including those in progress in Texas, cite reducing traffic as a primary goal.
“If you keep adding lanes because you want to reduce traffic congestion, you have to be really determined not to learn from history,” Dr. Turner said.
As many other people have explained, more lanes are not the main solution. Going from 1 to 2 or 2 to 3 may help, but any more just creates more “induced demand” and more traffic. More cars on the road guarantees more traffic.
There are highways, major streets, and side streets all over LA and NYC. Traffic is still terrible.