Arizona DOT commissioned a study a few years back showing that compact, mixed-use development actually reduces demand for driving and thus reducing congestion.

And that's only showing up to 10 people per acre, which is barely dense at all. Real gains start to reveal themselves at around 30 to 40.
California is dumping Level of Service as a metric because you know there is a problem when engineers give a grade A or F and economists give the exact opposite grade. Something is clearly amiss.
Tennessee, hardly the bastion of progress, says they will only be about building projects that are community-based and needed.