While I like the concept overall, I’ve been thinking about the same kind of business model and just want to quibble with one small detail: the anonymity of passengers is an inherent danger to the drivers. Reputation is very important to smooth P2P transactions, and consistent reputation tracking enables automating certain conflict resolutions (eg. optimistic tit-for-tat). Without symmetry in the reputation systems, one side of every transaction always has an unsustainable advantage against the other. I would agree that all sides should stay relatively anonymous to the payment system used outside each transaction, and to anyone else but confirmed drivers, but at most pseudo-anonymous (consistent face and rating avatar throughout each transaction) to the confirmed driver. This consistent avatar need not reveal a lot of personal information, but a face will enable smoother recognition at pickup, and a trustworthy rating value allows some ease in selection whenever more than one fare or action choice is available.