Example passenger validation systems and methods are described. In one implementation, a method receives, at a vehicle, a transport request indicating a passenger and a pick-up location. The vehicle drives to the pick-up location and authenticates the passenger at the pick-up location. If the passenger is successfully authenticated, the method unlocks the vehicle doors to allow access to the vehicle, determines a number of people entering the vehicle, and confirms that the number of people entering the vehicle matches a number of passengers associated with the transport request.