This European Standard specifies requirements for Road Traffic Signal Systems, including their development, design, testing, installation and maintenance.In particular, it forms the electrotechnical part of the following two standards issued by CEN:–EN 12368, Traffic control equipment ― Signal heads–EN 12675, Traffic signal controllers ― Functional safety requirementsEach of these standards above should be used with this standard either singly or together to define an operational equipment or system. This should be achieved by using the electrotechnical methods and testing defined in this standard.Where Road Traffic Signal Systems are to be used with other systems, e.g. public lighting or railway signalling and communication, this standard should comply with the other respective standard to ensure that overall safety is not compromised.Only permanently or temporarily installed Road Traffic Signal Systems are included in this standard. Central office and portable signalling systems are not covered.