This International Standard covers high-level safety requirements applicable to automated urban guided transport systems, with driverless or unattended self-propelled trains, operating on an exclusive guideway. This standard only deals with the safety requirements needed to compensate for the absence of a driver or attendant staff who would otherwise be responsible for some or all of train operation functions (see Table 1), depending on the level of automation of the system (see shaded areas in Table 1 and see 3.1 for a definition of the different grades of automation). The requirements of this standard are restricted to transports systems as defined in Clause 5 and to DTO and UTO as defined in 3.1.4 and 3.1.20, respectively (see the shaded areas in Table 1). This standard does not specifically look at security issues. However, aspects of safety requirements may apply to assuring security within the transport system. NOTE The definitions of “security” and “safety” are given by IEC 62278. Application of this standard is subsidiary to the responsibility of the transport authority and the safety regulatory authority (see IEC 62278) and to the specific laws and decrees applicable within the prevailing environment (economic, social, political, etc.) where the transport system is located, taking into account: • social risk acceptance in different cultures or different national legal regulations (e.g. SHOREI, BOStrab) or principles (e.g. GAME, ALARP); • laws and decrees in different states; • special or different requirements specified by the safety regulatory authority or by an independent assessor in charge of the specific application; • the responsibility for ”safe operation“ by the transport authority. This standard does not apply to the following types of transport systems, unless specifically required by the Transport Authority: • APMs (Automated People Movers) operating entirely inside a privileged environment such as an airport, a commercial centre or a leisure resort; • amusement rides and roller-coasters, generally featuring a single station so that passengers board and alight the system at the same location; • intercity and mainline train services, generally operating in a rural environment on part of their routes; • cable-driven systems; • systems featuring electronically guided vehicles with optical sensors, magnetic sensors, or similar devices/systems. This standard is not concerned with risks arising during works for construction, installation, modification and dismantling of a system. This standard is not concerned with pre-existing DTO or UTO systems (see definitions in 3.1) that were designed before this standard took effect. In the case of upgrading an existing transport system to a DTO or UTO system, the risks associated with the existing system are outside the scope of this standard. However, this standard and the risk analysis process described are relevant for the additional subsystems and possibly for the transition process itself. Therefore, the application of the standard is at the discretion of the safety regulatory authority. In the case of extending or modifying an existing DTO or UTO system in operation, this standard applies only if the change is significant as determined by the safety regulatory authority. However, the risks due to the relationship with the unchanged parts of existing systems (e.g. rolling stock, traction power supply, signalling and platforms) should be taken into account.