It was shocking to read The Power Broker last year and learn that since 1940s at least, urban planners have been aware of induced demand. Caro even brings up congestion pricing as a proposal that was rejected not because it wouldn't solve then problem but because the entire urban planning infrastructure was built to deny that there was a problem.
And this is why we have traffic today per that theory. Demand were induced and in a lot of cases cities didn’t end up building key reliever routes. So those initiall routes were overcapacity potentially from day one in the city.
It is also important to note that induced demand is not infinite. There is a point when there aren’t more drivers to actually get on the roads. We see this in some midwestern cities that had their full freeway plans built and didn’t experience significant growth after those plans were made. Those are “20 miles in 20 minutes” places any time of day for the most part.
