[tomtheelder]

https://www.numbeo.com/traffic/rankings.jsp

Best source I can find, suggests that travel times in Oslo are decent by world standards, and falls about where you would expect a US city of that size and density to be. It's conveniently right next to Portland, which was listed by the grandparent comment as a comparable.

The density required to have walking/biking/transit be realistic and efficient options makes over-subscribed roads a certainty unless you actively restrict automobile traffic. Private cars as the primary means of transportation works brilliantly in low to mid density areas, but fails utterly in high density ones.

There is no one size fits all solution for all cities. In my opinion it seems quite clear that there should be a negative correlation between density and private automobile usage in order to optimize safety and efficiency for all.