This document specifies steering system tests and performance criteria for evaluating the steering capability of wheeled, ride-on earth-moving machinery as defined in ISO 6165. Wheeled machines include machines equipped with wheels, one or more drums or crawler wheel assemblies. This document deals with the following significant hazards, hazarous situations or hazardous events relevant to wheeled machines, when used as intended and under conditions of misuse wich are reasonably foreseeable by the manufacturer: - mechanical hazarsd; - ergonomic hazards; - hazards due to maintenance; - hazards due to the control system; - hazards related to travelling function. Functional safety of the steering system is not covered in this document. This document is not applicable to wheeled machines manufactured before the date of its publication.