[kimixa]

True - the majority of the BART maintenance cost is the rolling stock not the track. How much does the average commuter spend on car maintenance and fuel? Or even the capital expenditure in the first place, if that commute is the difference between needing a(nother?) car for the household in the first place.

And costs like the drivers and station workers is just split over the 1-per-car drivers across an equivalent road. I don't know anyone who enjoys that commute, likely arriving more stressed rather than less, and you can't read or prep for your real work in any way when driving.

It's a common fallacy to ignore relatively small per-person costs, even if the total adds up to a massive amount due to the numbers of people.