Not ad hoc maybe, but if Uber prices would rise a lot I definitely could see a resurgence of the traditional "linger at busy nightlife area" style taxi where yo

Not ad hoc maybe, but if Uber prices would rise a lot I definitely could see a resurgence of the traditional "linger at busy nightlife area" style taxi where you just pay with cash. If the price differential becomes large enough that could draw enough customers back to "normal" taxi drivers.