A vehicle lighting system 1 reads position data of a plurality of nodes
which are situated ahead of and behind the current position of a cruising
vehicle using vehicle current position data and road map data to estimate
the shape of a driving path by connecting the plurality of nodes via an
interpolation process. Then, as to nodes which are recognized as change
points of the shape of the driving path by a road node characteristic
position detecting device 4, for example, a bending point or inflecting
point, and a starting point and a terminating point of a curve path, a
transition range is set ahead of and behind the nodes by a transition
range setting device 5. Then, when the cruising vehicle runs through the
range so set, a control quantity related to the illumination control of a
vehicle headlamp 10 is made to be changed slowly.