scope:

This European Standard specifies the functional safety requirements for traffic signal controllers. It is applicable to traffic signal control equipment permanent¬ly and temporarily installed, but excludes portable traffic control equip¬ment. Traffic signal controllers, as defined by this European Standard, are required to control conflicting traffic, both vehicular and pedestrian, e.g. junction signals, pedestrian crossings, shuttle signals, public transport signals, in a safe manner. The electrical safety requirements and additional traffic safety requirements, the interfacing with external equip¬ment and the test methods for verifying compliance with this European Standard are contained in HD 638. NOTE - National requirements may specify special conditions for public transport signals (PT) and for any other signal that is not specified in a European Standard.