> You're seriously arguing that cryptography has no technical means for a driver to send an unrepudiatable attestation of intent to drive from A to B at time C to an anonymous passenger? And that an ombudsman armed with driver GPS data cannot compare the attestation to the GPS data and instead needs identification data on the passenger in order to verify whether the driver went to the correct drop-off?

There are at least three things you need here:

(1) the agreed trip, and

(2) that the passenger showed up and got in,

(3) that the passenger did not make some demand that ended the driver's obligation to make the agreed trip en route.