Are smarter cars driving us to distraction?
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Hi-tech features from sat-navs to voice-activated music systems are designed to help drivers, but scientists are discovering how distracting they are too.

Not so long ago choosing a new car was relatively straightforward. After cost, and possibly colour for some, primary considerations were things like engine size, performance and fuel efficiency.

These days, manufacturers are making our choices more difficult by adding all manner of advanced tech features, from in-built sat-navs and parking assistance to voice-activated or touchscreen DVD players and radios. While these systems can undoubtedly improve the driving experience, there are fears they may also be too much of a distraction for drivers, and make roads more dangerous as a result.

Minimising distraction was one of the topics explored at the recent Connected Car Expo in Los Angeles. Scientists and engineers discussed some of the new tools and methods they are developing to improve our understanding of the issue, which in turn could hopefully provide some solutions.

For example, researchers led by Bruce Mehler at MIT in Cambridge, Massachusetts, are assessing driver distraction using an advanced driving simulator – basically a full car inside a lab equipped with display screens – as well as adapted vehicles driven on real roads. In both types of experiment, a range of sensors measure driver behaviour like when pedals are pressed and how hard, and also collect data on their vital signs like heart rate and sweat gland activity from the fingers. Cameras track drivers’ eyes while they are driving under a variety of test conditions.

The video above shows one of the tests carried out. Subjects were asked to change the radio station either manually or using voice control. They were also instructed to repeat numbers being read out, only sometimes they have to repeat those one or two back in the list. The idea was to test how driving is affected by increasing the amount of information the brain deals with, or the “cognitive load” as it is known.

This research has already revealed some intriguing findings. A recently released study shows that drivers using voice command interfaces to control in-car navigation systems or USB-connected music devices can sometimes spend longer with their eyes off the road than those using conventional systems.

‘Eye opening’

Voice activated systems in newer radio systems would seem to offer an advantage over older car radios of keeping the drivers eyes on the road. (Indeed, tuning an older radio was used as a baseline task in these tests.) But according to Mehler, problems arise when the system needs clarification of what the driver wants, such as when inputting an address into a navigation system. 

A user could say, for instance, “I want to go to Boylston St”, but the car could find a Boylston St, Boylston Av, and Boylston Circle. Those options are repeated to the driver, who is asked to select one.

“I could use voice, and answer that, and keep my eyes on the road,” says Mehler, a research scientist at the MIT AgeLab and New England University Transportation Center. “But now I’m keeping a fair amount of information in my head, and that could create a level of cognitive demand which makes it harder to attend. So although I am looking at the road, I may not be seeing things on the road.”

One way some manufacturers get around this is to present lists of options on display screens. Research backs this up: it shows that drivers can take a quick glance and select an option safely.

However, the way drivers interact with their in-car systems tells only part of the story. Human behaviour also needs to taken into account. Mehler describes a recent study that examined the driving habits of both frequent and infrequent cell phone users as “really quite eye opening”.

According to Mehler: “People who report using their cell phones frequently, even when they don’t have it in their hand, drive faster, drive more aggressively.” The study showed frequent users drove almost 5kph faster, switched lanes twice as often, spent more time in the far-left lane, and were more likely to slam on the brakes. “They’re likely to do things in the car that some of the rest of us wouldn’t be comfortable with doing,” he says.

So what makes for less distracting car features? In April this year, the US National Highway Traffic Safety Administration released voluntary guidelines on the subject for manufacturers, recommending systems are designed so that divers don’t take their eyes off the road for more than two seconds at a time, or 12 seconds in total per interaction or task. The guidelines come after a study by the NHTSA showed that hand-eye coordination tasks (such as using a cell phone) made it three times more likely a driver would crash.

But researchers working in this field are well aware that drivers want access to an increasing range of information, from navigation prompts to social media updates. Therefore blocking this information altogether is not realistic. According to Mehler, if the in-car tech locked people out when vehicle were in motion, they would just pick up their phones. In which case they would be back to square one.

People are always going to want to be connected, he says. “The real challenge is to understand how you can develop interfaces that balance demands, to find optimal routes for people to do these things.”

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