When an autonomous driving vehicle picks a user up, a control device performs departure condition confirmation processing. The departure condition confirmation processing includes first authentication processing that performs authentication of the user outside the autonomous driving vehicle based on first authentication information, door lock release processing that releases a door lock in response to the completion of the first authentication processing, second authentication information provision processing that makes the user acquire second authentication information different from the first authentication information in response to the completion of the first authentication processing, second authentication processing that performs authentication of the user inside a vehicle cabin of the autonomous driving vehicle based on the second authentication information, and start permission processing that permits the start of the autonomous driving vehicle in a case where the second authentication processing is completed.