An Intelligent Transportation System, ITS, service station is disclosed. The ITS service station has: a receiver having an area of radio coverage and configured to receive a first Collective Perception Message, CPM, from a first ITS station at a first position within the coverage area, the first CPM including first sensor data on at least one first free space area perceived by the first ITS station; an aggregator configured to aggregate said first sensor data with at least one second sensor data on at least one second free space area into a third sensor data, which second sensor data is received via the receiver in a second CPM from a second ITS station at a second position within the coverage area or is determined by a sensor of the ITS service station; and a transmitter configured to broadcast said third sensor data in a third CPM.