REGISTER

Christian Wullems BIT(Hons) PhD MIEEE MACS

Cooperative Research Centre for Rail Innovation

George Nikandros BE CPEng FIRSE MIEAust MACS (Snr)

Australian Safety Critical Systems Association

Peter Nelson-Furnell B.Bus(Transport)

Public Transport Victoria

Low-cost level crossings are often criticised as being unsafe. Does a SIL (safety integrity level) rating make the railway crossing any safer? This paper discusses how a supporting argument might be made for low- cost level crossing warning devices with lower levels of safety integrity and issues such as risk tolerability and derivation of tolerable hazard rates for system-level hazards. As part of the design of such systems according to fail-safe principles, the paper considers the assumptions around the pre-defined safe states of existing warning devices and how human factors issues around such states can give rise to additional hazards.