ADR (Accord europeen relatif au transport international des marchandises Dangereuses par Route) is the European agreement governing the transport of dangerous goods by road. A tractorhead with ADR approval incorporates specific modifications to its electrical installation, exhaust system, fire protection and safety equipment that distinguish it from a conventional tractor unit.
The ADR classifies dangerous goods into 9 main classes, each with specific vehicle requirements:
An ADR-approved tractorhead must incorporate the following elements per European standards:
ADR tractorheads are classified by vehicle type according to the classes they can carry: