This International Standard describes two open-loop test methods for determining on-centre handling characteristics of a vehicle in response to specific types of steering input under closely controlled test conditions: - the weave test, and - the transition test. This International Standard applies to heavy vehicles, i.e. commercial vehicles, commercial vehicle combinations, buses and articulated buses as defined in ISO 3833 (trucks and trailers with maximum weight above 3,5 tonnes and buses and articulated buses with maximum weight above 5 tonnes, in accordance with ECE and EC vehicle classification, categories M3, N2, N3, O3 and O4).