Here is a snip from a Q&A traffic column called “Roadshow” in the Silicon Valley. This makes me never want to park in the regular on-airport lot at SF again, and why, since there are so many other options for off airport using airportparkingreservations.com for lower cost and no risks.
Q FasTrak can be used to pay parking charges at San Francisco’s long-term airport parking. Unfortunately, there do not appear to be any controls to avoid duplicate charges if the parking has already been paid by credit card. I paid my parking fee at a self-serve kiosk in the parking structure, using a credit card. When I exited, the machine asked for the ticket, which I put in the machine, after which the gate lifted. I then heard my FasTrak beep. I went back to the attendant and he confirmed that there is a problem where FasTrak will ding you for parking, without first checking if the ticket is already paid. Parking folks tell me I am not the only one getting double charged.
A SFO, we have problems. Airport officials say there have been sporadic cases of duplicate charges and they are trying to resolve a software problem. If this happens to others, call the airport at (650) 821-4051.