[I meant to send this way back and realized I never did!]
Thank you Bobbi for the excellent suggestion. Here is the podcast you mentioned:
Should Traffic Lights Be Abolished? (Ep. 454) - Freakonomics Freakonomics
As the Mayor of Carmel, Indiana mentioned, this suburb of Indianapolis has grown enormously (from ~25,000 in 1996 to over 101,000 people now).
https://en.wikipedia.org/wiki/Carmel,_Indiana (BTW: basically all at the expense of center-city Indianapolis).
But at least that explosive growth allowed them to build out some brand-new infrastructure smartly. It is kind of like when cell-phone networks first appeared and the developing world (Asia, Africa, Latin America) actually had better cell-phone infrastructure than many parts of the USA. That was due to being hobbled with the double cost of maintaining all the existing and lower-performing incumbent infrastructure while ramping up to find the resources to build out a new, better generation of technology. That is exactly what Portland is struggling with now. It has been a hugely expensive (and LONG) expedition to build the USM roundabout and it will take a very long time for it to pay for itself in terms of benefits.