2014 – July – Naweed & Aitken – Drive a mile in my seat: signal design from a systems perspective

Anjum Naweed BSc MSc PhD Central Queensland University John Aitken BE MIRSE SMIEEE Aitken & Partners Train drivers navigate conventionally designed railways using a keen awareness of their routes and by calculating likelihood predictions of future states. These processes have traditionally followed a model of signal-to-signal based running, which comprises the awareness of their static (location-based) and dynamic (aspect-related) properties. This paper reports findings from a study that examined the socio-cultural and technical ties between the signal and the driver in the context of SPAD risk management. It provides examples of how signal aspects are being interpreted on Australasian railways, how operational pressures are altering the driver-signal dynamic, and how the meaning of the caution aspect has evolved in today’s dynamic and productivity oriented rail environment. The paper seeks to describe the train drivers’ experience of interpreting and responding to railway signals, so that the signal engineering community may better understand the implications of introducing new variables and schemes into their signal design language.