The present invention relates to an illumination control system comprising a plurality of outdoor luminaries and a motorized service vehicle. Each luminaire comprises a controllable light source producing a light illuminance. The motorized service vehicle comprises a light sensor configured to detect the light illuminance generated by the controllable light source at the motorized service vehicle. The motorized service vehicle computes light illuminance data based on the detected light illuminance and transmits these to the outdoor luminaire through a wireless communication link or stores the light illuminance data on a data recording device of the motorized service vehicle. The outdoor luminaire receives may use the light illuminance data to set or adjust a light illuminance of the controllable light source.