This research examines cognitive demands of collision avoidance under a range of maritime scenarios. Operators used a PC-based radar simulator to navigate set courses over 100 6-min trials varying in collision threat and traffic density. Corrective actions were taken through application of standard navigation rules and by using 2 decision aids. Results show widespread effects of collision threat in terms of decision aid use, subjective workload, and secondary task performance. Demand increased markedly over the course of emergency trials, in which collision threat resulted from rule violation by target vessels. Findings are discussed in terms of the comparison between predictable demands and those involving uncertainty about the others' intentions. The study is relevant to design of collision avoidance systems, specifically for use with ecological displays.
Abstract