"The concept is called induced demand, which is economist-speak for when increasing the supply of something (like roads) makes people want that thing even more. Though some traffic engineers made note of this phenomenon at least as early as the 1960s, it is only in recent years that social scientists have collected enough data to show how this happens pretty much every time we build new roads." https://www.wired.com/2014/06/wuwt-traffic-induced-demand/
What's Up With That: Building Bigger Roads Actually Makes Traffic Worse

The concept is called induced demand, which is economist-speak for when increasing the supply of something (like roads) makes people want that thing even more. Though some traffic engineers made note of this phenomenon at least as early as the 1960s, it is only in recent years that social scientists have collected enough data to show how this happens pretty much every time we build new roads.

WIRED
@freakonometrics This tracks ... the 405 freeway is 12 lanes across in some parts of Los Angeles, and regardless of how big they make it, it's always at a dead standstill every workday between 4 and 7 PM.
@freakonometrics @klausfiend I was once stuck going uphill on northbound 405 near the Getty. Right next to me was Eddie Murphy. Beautiful sports car, top down, beautiful S. California day …but he was going nowhere. I wanted to say hello but he was supremely angry and yelling into his phone. The 405 will do that to people.
@meltedcheese @freakonometrics Pretty sure the 405 exists just to break hearts ... I remember one Wednesday, I drove to the west side to hang out; there was a fire that day in Agoura Hills or something like that, and at 5 PM, the 405 was a parking lot. Hung out, went for pints, 4-5 hours later, it was STILL a parking lot.
@meltedcheese @freakonometrics oh, and then there was the time there was a drive-by _on_ the 101, and they had to shut down the freeway for hours to collect evidence, nobody on, nobody off ... LA has a special and very dysfunctional relationship with highways.
@klausfiend @freakonometrics I had the exact same experience as well as many variations during my 23 years in LA. I learned that 4am was the sweet spot for driving across the city. Too late for the bar crowd, too early for rush hour. If I had an 8am flight out of LAX, I left home in Pasadena at 4am. Any later and I would surely miss my flight.