VEHICLE LAMP SYSTEM, CONTROL DEVICE, ILLUMINATING STATE RESTRICTION METHOD, AND RECORDING MEDIUM

A vehicle lamp system includes: a vehicle lamp that can form a high-beam light-distribution pattern in which a state of illuminating one or some illuminated regions is changed among illuminated regions that are separate in a vehicle-width direction; and a controller that can control the vehicle lamp to restrict the state of illuminating the one or some illuminated regions, based on position information having a correlation with the position of a vehicle ahead. The controller calculates a predicted position to which the vehicle ahead is predicted to move after a fixed time period from a reference time, based on the position information acquired anew at the reference time, an amount of change in position of the vehicle ahead calculated from pieces of the position information acquired during a predetermined time period before the reference time, and information on a travel road on which the vehicle ahead travels.