200311 – Coleman & Slamen – The Application of Human Factors to the Development UK Standards for VDU Based Signalling Control Systems

Across the UK Rail infrastructure a number of alterative approaches to the development of VDU based signalling control systems (VSCS) are being adopted by different companies in order to meet the demands of improved railway safety and performance. The systems incorporate different signaller – system interaction design models; interface functionalities; alarms systems and schematic layout conventions.

While Railway Group and Network Rail Company standards largely address the technical and
functional requirements to ensure compatibility across the UK network and between its systems,
they have historically left important HMI safety critical areas (e.g. alarms, aspects of visual
coding) open to designer interpretation. Further, VSCS designers complain that where interface
requirements have been specified they can be too restrictive – being prescriptive and based on
older technologies – and in some cases, actually promote poor interface design solutions.

This paper introduces the work that Human Engineering has undertaken in conjunction with the
Network Rail Ergonomics Group in order to ensure that human factors requirements and
guidelines are properly incorporated into revised and new Network Rail standards for VSCS
design. It outlines the issues and processes involved; the adopted approach; and provides
specific examples concerning the development of requirements for signalling schematic maps
and alarms systems.