You cannot travel across borders without a passport. A Carnet de Passage en Douane (CPD) can be seen as a ‘passport’ which allows your vehicle to be temporarily imported into a foreign country while you overland.
What exactly is a Carnet?
Most people refer to a Carnet de Passage as a Carnet or CPD. It is an international customs document which offers a guarantee to a foreign government that the vehicle identified in the Carnet, if granted temporary importation status, will be removed from the country within the specified time limit. In the event that the vehicle is not removed within that time frame, the country may claim from the authority who issued the Carnet all duties and taxes that would be required to permanently import the vehicle to that country.