One embodiment of an unmanned carrier for carrying urban manned vehicles includes a computer, a motorized lift, an autonomous-driving control system, and a safety frame. The computer synchronizes pick-up of manned vehicles by the unmanned carrier; wherein each manned vehicle is an autonomous on-road vehicle that transports one or more occupants in a compartment, is authorized by law to drive in a residential neighborhood, and is unauthorized by law to drive on the highway on its own because it is not safe enough for highway speed. The motorized lift enables the manned vehicles to get on and get off the unmanned carrier without human intervention. The autonomous-driving control system navigates the unmanned carrier autonomously on a highway. And the safety frame protects the occupants who sit in the carried manned vehicles during a collision at highway speed.