1. a Centre for Rail Human Factors , Institute of Occupational Ergonomics, University of Nottingham , University Park, Nottingham, NG7 2RD, UK
2. c School of Safety Science, University of New South Wales , Sydney, NSW 2052, Australia
3. b Ergonomics National Specialist Team , Network Rail, 40 Melton Street, London, NW1 2EE, UK