Looking for a way to measure how aware drivers are of what’s happening on the road around them when they’re using partial automation, the latest innovation from the Insurance Institute of Highway Safety isn’t a new crash test, it’s a giant pink teddy bear.
IIHS researchers dressed an enormous stuffed bear in a high-visibility jacket and strapped it to the back of a car. They then compared whether three different groups of drivers noticed the bizarre tailpiece when the vehicle overtook them as they motored down an interstate in Maryland.
Alexandra Mueller, IIHS Research Scientist, who developed the concept – says it’s not as strange as it sounds. She credits the ‘weirdness’ as what makes it work, stating that there are a number of laboratory methods for measuring situational awareness that don’t work so well on the road. The giant teddy bear on the back of the vehicle helps to give an objective measure of the driver’s focus that is relevant to driving and doesn’t interfere with how that person normally drives.
That measure is useful because today’s partial automation systems are still not fully autonomous.
To test the concept, IIHS observed 31 drivers as they drove a 2019 Mercedes-Benz C300 for about an hour on a Maryland stretch of I-70. One set of drivers, who regularly used similar Level 2 systems in their own vehicles, drove with the partially automated feature switched on – as did another group of drivers who had little or no experience with these types of systems. A third group that was also unfamiliar with Level 2 automation completed the trip in the same vehicle but left the automation switched off.
During the trip, the vehicle with the pink teddy bear overtook each driver three times and remained in view approximately 30 seconds. Cameras inside the test vehicle recorded where the driver was looking, as well as the view of the road through the windshield. After the trip, the drivers were asked whether they had seen anything odd about any vehicles they had encountered and, if they had, how many times they had seen it.
The researchers observed clear differences in how successfully the three groups of drivers took note of the hard-to-miss bear, suggesting that the method effectively provided an objective measure of situational awareness.
More than twice as many inexperienced Level 2 automation users who were driving with the system turned on failed to recall the bear at all compared with the other groups. Almost all of the frequent Level 2 automation users who had the vehicle’s system switched on noticed the bear. They were also more likely than the other groups to correctly recall the number of times it had appeared during the drive.
Researchers also analyzed the video data and found that drivers who better recalled the bear also tended to spend more time scanning the forward roadway, as well as looking out the driver and front passenger windows, where the bear emerged into view as the vehicle carrying it passed them. In contrast, drivers who missed the bear tended to spend more time looking straight ahead.
Though the sample was small, these results suggest that partially automated driving systems have the potential to improve drivers’ situational awareness after they have gained experience using the technology. Inexperienced drivers may have more difficulty keeping track of what’s going on around them when using the unfamiliar technology than when driving without it.
On the other hand, previous studies have shown that familiarity with automation can also have drawbacks. Users can become complacent as their trust in the technology grows. That makes them more likely to check their phones or fiddle with the navigation or audio system than they would do while driving manually – a problem that has already been implicated in several serious crashes.