For arrivals, SFO has signs that direct passengers to a designated rideshare pickup area, and the rideshare apps direct passengers to a designated stall.

It would be possible to monitor how many cars are picking up passengers there with cameras, because non-rideshare cars would not pick up people there. It would also be possible for an auditor to spot-check with the Uber app and see if they get charged the fee or not, and whether the app directs them to the rideshare pick up area. From there it’s easy to see if a company is circumventing the surcharge.