Remember also that existing transit links are beyond fully saturated. It’s not really possible for people to switch to transit en masse before the decades it takes us to build bus terminals and train tunnels have elapsed. No public transit system has the slack to absorb the Bay Bridge drive-alone traffic, let alone 101 or 280. People physically won’t fit into the vehicles. There are decade-scale projects to address that, and I support them, but I don’t expect to see their fruits during my working life. Anyone working now is going to be retired by the time a second Transbay Tube starts passenger service, assuming we vote to fund it right now.
Here [0] is an article to covers parts of this exact subject.
[0]: https://www.eastbaytimes.com/2013/08/09/building-the-bay-bri...
Instead, we got a less-safe, grandiose art piece for over $8 billion. $400 million more if you want a bike lane.
What makes you think European engineering companies are any better? Europe is just as littered with failed, bloated, late and vastly over budget infrastructure projects. Hell the small bridge down the road from my office was supposed to be closed for 4 month for some maintenance work, it's now been closed for 14 month and there is still no estimate for when it will be done.
The New York City subway was built in the era of Boss Tweed
Road damage is proportional to the 4th power of the vehicle weight. Normal cars effectively do nothing to roads. The damage comes from buses, fire trucks, UPS trucks, FedEx trucks, bucket trucks... and more trucks.
Switching all that to rail is completely unreasonable. Fire departments getting around on rail?
So we need the roads anyway, and cars don't wear them out. Cars do not impose a cost. As it is, car drivers are paying money to fix roads that are being damaged by buses.
What if we charged bus passengers the true cost of taking the bus? Each passenger on a bus is contributing to road damage. Each driver in a car doesn't cause damage.
How many lanes would we need if there were only trucks on the road? We build massive road capacity to subsidize car use.
So, on average, we don't really have more lanes than the minimum.