A system comprising: one or more road-side illumination sources arranged to emit illumination to illuminate at least part of a road; one or more detectors arranged to detect a value of one or more parameters of a vehicle travelling on this road or this part of the road, the one or more parameters comprising a type of the vehicle and/or an identity of one or more users of the vehicle; and a controller arranged to control the illumination emitted by the one or more illumination sources, wherein the controller is configured to adapt the illumination in dependence on the detected value or values of the one or more detected parameters.