prSRPS EN 50556:2019/A1:2026

Road traffic signal systems

Scope

This document specifies requirements for Road Traffic Signal Systems, including their electrical operating conditions, electrical
safety and operational safety, testing, electrical interfaces, installation, maintenance and marking / labelling.
This document forms the electrotechnical part of the following two standards:
— EN 12368, Traffic control equipment ― Signal heads;
— EN 12675, Traffic signal controllers ― Functional safety requirements.
The above standards are used, either singly or together with this document, to define an operational equipment or system. This
will be achieved by using the electrotechnical methods and testing defined in this document.
This document is applicable to traffic signal control equipment permanently and temporarily installed, and portable traffic control
equipment, with the exception of portable traffic signal equipment only capable of controlling alternate / shuttle working lanes (as
further defined in this document).
Where road traffic signal systems are to be used with other systems, e.g. public lighting or railway signalling and communication,
this document will be used with other relevant standard(s) such that overall safety is not compromised.