Assessing the 'system' in safe systems-based road designs: using cognitive work analysis to evaluate intersection designs.
While a safe systems approach has long been acknowledged as the underlying philosophy of contemporary road safety strategies, systemic applications are sparse. This article argues that systems-based methods from the discipline of Ergonomics have a key role to play in road transport design and evaluation. To demonstrate, the Cognitive Work Analysis framework was used to evaluate two road designs - a traditional Melbourne intersection and a cut-through design for future intersections based on road safety safe systems principles. The results demonstrate that, although the cut-through intersection appears different in layout from the traditional intersection, system constraints are not markedly different. Furthermore, the analyses demonstrated that redistribution of constraints in the cut-through intersection resulted in emergent behaviour, which was not anticipated and could prove problematic. Further, based on the lack of understanding of emergent behaviour, similar design induced problems are apparent across both intersections. Specifically, incompatibilities between infrastructure, vehicles and different road users were not dealt with by the proposed design changes. The importance of applying systems methods in the design and evaluation of road transport systems is discussed.
Monash Injury Research Institute, Monash University, Melbourne, Australia. Electronic address: miranda.cornelissen@monash.edu.
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Cornelissen
Monash Injury Research Institute, Monash University, Melbourne, Australia; University of Sunshine Coast Accident Research, Faculty of Arts and Business, University of the Sunshine Coast, Maroochydore, Australia.
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Salmon
Civil, Maritime, Environmental Engineering and Science Unit, Faculty of Engineering and the Environment, University of Southampton, United Kingdom.
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Stanton
Monash Injury Research Institute, Monash University, Melbourne, Australia.
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McClure
D000063:Accidents, Traffic / Q000517:prevention & control*; D001315:Australia; D001334:Automobile Driving / Q000523:psychology*; D003071:Cognition / Q000502:physiology*; D004779:Environment Design; D006801:Humans; D012449:Safety; D013597:Systems Analysis
Cognitive work analysis; Intersection design; Safe systems; Strategies analysis diagram; Systems approach