Automotive industry is constantly trying to improve vehicle safety and make driving a car a more relaxed and pleasant experience. There are more and more electronic systems involving in solving this quest. However, not all of them may be good for the safety.
Now scientists from University of Toronto have noticed that augmented-reality displays, which present digital images directly on windshield, are actually a threat to safety rather than a helpful feature.
Such augmented-reality head-up displays can show images to alert drivers of different things – from possible collisions to smart phone activity – they are designed to make driving safer. However, as professor Ian Spence notes, it is not that helpful and might even be dangerous as driver needs to divide his attention between road and this added visual information. “Not only will drivers have to concentrate on what’s happening on the road around them as they’ve always done, they’ll also have to attend to whatever warning pops up on the windshield in front of them”, he explained.
To test what kind of effect such displays have on driving safety, teams of researchers designed two tests. At first, participant of the study completed a series of computer-based trials. Here they had to report a number of randomly arranged spots (between one and nine) displayed on a screen as quickly and accurately as possible when prompted. On some of these trials there was some additional stimulus in the form of a black-outlined square. Scientists asked participants if they saw the square. This square appeared together with the spots and only in some of the trials in unpredictable fashion.
Scientists found that when square was not appearing on the screen accuracy was high, which suggests that little attention was required to confirm that the square was absent. However, when the square appeared with several spots, it was missed about one in 15 times on average.
With higher number of spots, this rate increased to one in 10 instances, which suggests that when attention is occupied by the primary task, participants will have more difficulty attending to the secondary task stimulus. Furthermore, scientists also found that as number of spots increased, participants were less accurate reporting the number of spots also, which may mean that when a primary task becomes more demanding both tasks compete with and interfere with each other.
As good as these tests are in terms of checking the attention division between two tasks, they do not fully reflect the real life situation. It is much more demanding to drive an actual vehicle. Not only drivers have to see and identify what they see, but they also have to react accordingly. Scientists say that because of that it is important to make a division between two kinds of information displayed on the windscreen – warnings in a dangerous situation and simple suggestions (for example, to make a turn). If such division is not made, competing warnings may do more damage than help.
The second part of the research was made to test this principle. Scientists asked participants to identify the appearance of a random distinctive shape – a triangle, a square or a diamond – among the spots. The shape appeared along with the spots in an unpredictable fashion like before. The test was designed this way because the message about what is happening outside of the vehicle would appear randomly too.
Scientists found that with larger number of spots, participants often misidentified or missed the shape. Also, as with the first experiment, estimating the number of spots was also more difficult when the random shape appeared on the screen. Participants were also much slower when trying to fulfil the tasks – made both judgements more slowly when the shape appeared among the spots by as much as 200%.
It means that actual road ahead and messages from augmented-reality head-up displays compete for driver’s attention and make it less safe. This is especially true for demanding driving environments. Hopefully, this new knowledge will be taken into account when developing other electronic equipment that may demand attention from the driver. At the end of the day, safe journey is the ultimate goal of everyone involved in automotive industry.