They are always innovating out there in San Francisco:
The Golden Gate Bridge, Highway and Transportation District is considering collecting tolls exclusively electronically on the bridge by December 2012. …
After the $3.2 million start-up costs, collecting tolls all-electronically will save the district $16.3 million over 10 years. …
[O]nly 33 percent of Golden Gate Bridge tolls are collected manually. …
Among the new toll-paying options that will replace cash payments are expanding the FasTrak program and paying the toll based on the vehicle license plate. The license plates of tourists and other infrequent users of the bridge will be read and they will be sent a bill for the toll.
They will be able to pay with a check or money order through the mail. They also will be able to pay the toll over the phone with a debit or credit card while they are still in the Bay Area.