I'm very familiar with the real costs sadly, I do pretty much all my own mechanic work as well as insurance rate shopping etc.. I think the cost is even higher in stress on the road while driving personally, and I try to drive less then once a week if I can help it. Unfortunately depending on the job, I often have to drive a work pickup several times a week but that doesn't cost me anything and I like to drive that truck like a little old lady.
I agree with your theory about true high speed and costs, but it's not. Despite having to get retrofitted tracks etc etc etc, the top speed being 79MPH, which it often won't be doing as it crosses roads/towns/etc. The measure was passed easily as they proposed an accompanying pedestrian/cyclist path for the entire 70 mile stretch of the project. Heck I voted for it and I don't plan to ever ride the train! Now it's "tough cookies" as the path will be put in whenever, and the rail line priority is now only from the affluent south end to our counties main city as in.. it's a tourist pipeline in the making, which is fine as most of our economy here is based on tourism (wine country). But I personally would never have voted for it had I known the path would be put on the backburner.. I rather looked forward to being able to cross the entire county on dedicated non motorized infrastructure.(they do intend to finish the complete rail line/path, but it's a "whenever" thing now)