Variable speed limits are automatically controlled (with artificial intelligence), taking into account the weather, road conditions and the traffic situation. Variable speed limit signs can also be controlled manually by the Traffic Management Centre.

Both the variable speed limit and warning signs and information displays usually operate on the so-called proposal principle, which means that the road weather station suggests the speed limit to the system automatically. The control system is monitored and managed by an officer on duty at the Traffic Management Centre who makes sure that the limit suggested by the system is applicable for the current weather and road conditions.