Human factors research to support effective evaluation of in-vehicle systems: A case study example

Intelligent Transport System (ITS) technologies are increasingly being used in a number of ways with drivers now having access to a range of information, communication and entertainment systems, as well as driver aids, collision avoidance technologies and a wide range of portable devices. While it is clear that the integration of ITS technologies within the vehicle could potentially have a range of safety and performance benefits, they also have the potential to degrade safety if not designed or used properly. Before entering vehicle fleets, new technologies need to be rigorously evaluated to ensure that they do not impose a safety risk. At MUARC the mid-range driving simulator has been a critical tool for such evaluations. This paper will outline how our research is supporting the effective evaluation of in-vehicle technologies through the discussion of a recent evaluation of an in-vehicle system to warn drivers of an approaching emergency vehicle. Through systematic scenario design and behavioural analysis in the driving simulator it was possible to determine when drivers first detected the warning through analysis of eye-movement data, and to determine when they first responded through analysis of driving performance data. While the device had positive effects on safety through reductions in driver speed, the data provided for a theoretical consideration of how drivers respond to warning systems in this context. Warning signals need to provide the driver with reliable information in a salient manner, minimising distraction, and issues relating to the warning timing and mode of presentation are critical here. Priming theory emerged as a likely mechanism underpinning the observed safety benefits and is generalisable to other settings where an advisory warning is presented before the threat is perceived.