But it's very much like that. The approval process is extremely inefficient in the US. As you said, "building" the red line is not hard, but getting it through

But it's very much like that. The approval process is extremely inefficient in the US. As you said, "building" the red line is not hard, but getting it through the permitting gauntlet is. After a certain level of saturation these things just get easier. See road construction, expansion, etc. It's the default, yet it's clear that "just one more lane" won't solve traffic. Regarding buses (and public transport in general): what's the utilization of the existing capacity for SF and Zürich? It would be interesting to compare number of buses, total distance driven, and other parameters for these rider numbers. Also do you happen to know anything about cost breakdown? (My guess is that Zürich is simply a lot more dense, and public transport is just the default there, whereas it's not in SF.)