This part of ISO 10865 is applicable to wheelchair passenger spaces (RF-WPSs) intended for use by rearward-facing wheelchair-seated occupants, with a body mass greater than 22 kg, when travelling in accessible transport vehicles. It is applicable to systems for use in vehicles used mainly on fixed route services when operated under normal and emergency driving conditions, where passengers are allowed to travel both sitting and standing. It assumes that the maximum acceleration imparted to the vehicle in any direction during emergency driving manoeuvres will not exceed 1g. This part of ISO 10865 specifies design and performance requirements and associated test methods, requirements for manufacturer instructions and warnings to installers and users as well as requirements for product labelling and disclosure of test information. The primary purpose of this part of ISO 10865 is to limit those movements of a rearward-facing wheelchair, including scooters with three or more wheels, that can result in hazardous contact with the vehicle interior or injury to other passengers. The provisions of this part of ISO 10865 apply primarily to a complete RF-WPS, but subsets of the provisions can be applied to components and subassemblies sold separately, as appropriate to the specific functions of the components and/or subassemblies they are intended to replace.