Controlling vehicle platooning

A distributed vehicle platooning system comprises a core layer including a central server 300; an edge (middle) layer comprising local cell servers (e.g. cellular base transceiver stations (BTS)); and a vehicle layer comprising vehicles 100. A vehicle platooning controller (106, Fig.1) transmits a journey constraint to the central server to enable generation of cell constraints; receives platoon-in-cell information dependent on the cell constraints from respective local cell servers during the journey; and controls vehicle speed, direction or platoon position in dependence on the platoon-in-cell information. The journey constraint may be a destination, arrival time, starting time or current location and may be confidential. The cell constraints may be speed profiles or inter-vehicle distances and may depend on route conditions (e.g. traffic, weather, road or road elevation). The platoon-in-cell information may be a speed profile, inter-vehicle distance or platoon position and may have a finer level of detail than the cell constraints and vary throughout the cell.