Just as a counter point. You talk about San Francisco's roads and how well they function. During the 1989 Loma Prieta Earthquake several major freeways in San Francisco were badly damaged, especially the Embarcadero Freeway and large parts of the Central Freeway, both multi-lane free flow freeways with off-ramps. The damage was so extensive that both were pretty much demolished outright and converted into at-grade boulevards with multiple signalized intersections.
And guess what? Traffic imrpoved. Not only that, there was considerable redevelopment where the Embarcadero used to be, around what is now Pier 39, which, as a tourist, I am sure you visited.
Just a counter point to saying that San Francisco's success is based on large roads with free flow traffic. Removing a major freeway improved traffic in the long run.
Check out a UofT study on this called "The fundamental law of road congestion". This isn't a select few cases, it is a well studied relationship.
http://www.parisschoolofeconomics.eu..._seminar3b.pdf