[saghm]

It's been quite a while since I rode BART (I interned in SF in 2014, and visited briefly again I think in 2015), but I remember noticing that in the list of fares for different stops from the given station you're in, riding to the end of the line was actually cheaper than stopping at the airport (the second-to-last stop IIRC) on one of the lines. Basically, since they knew more people would get off at the airport than the stop past it, they charged more to get off there. I never did ride all the way to the end of the line, but I assumed that they made sure to hike the price from that stop to the airport as well so you couldn't purposely go there, get off, and then reboard to save a few bucks (although I imagine the time spent doing that wouldn't really be worth it to most people anyhow).