Study: Voice systems eliminate some driver distractions

David Shepardson
Detroit News Washington Bureau

Washington — Voice recognition systems help keep drivers eyes on the road but they don't eliminate visual distraction altogether, a new study by researchers from IIHS and the Massachusetts Institute of Technology's AgeLab found.

The study also found significant differences in hands-free systems.

The research comes as the National Transportation Safety Board and some other groups have called for barring most hands-free calls, citing the risks of distraction. But so far those calls haven't gained significant support; no U.S. state currently bars hands-free calls.

"In an ideal world, drivers wouldn't do anything but drive while the vehicle is moving. But people are increasingly plugged in at all times, and automakers have responded by installing systems to make it easier to use technology on the go," says Ian Reagan, an IIHS senior research scientist and a co-author of a pair of papers based on the study. "While you can't completely eliminate the distracting nature of these types of tasks, this study shows it's possible to reduce some types of distraction through system design."

This study didn't measure cognitive distraction. The study showed "the voice interfaces still led to modest changes in driving performance and increases in stress levels relative to periods when drivers were just driving," IIHS said.

In the study conducted on interstate highways in the Boston area with 80 drivers age 20-66, half drove a Chevrolet Equinox equipped with the MyLink system, and half drove a 2013 Volvo XC60 with the Volvo Sensus system. All participants used a Samsung Galaxy S4 smartphone programmed with the same list of more than 100 contacts and mounted in the center console area.

IIHS said none of the systems eliminated all glances away from the road when calling, but they reduced total eyes-off-the-road time compared with manual calling. When using the smartphone with voice commands, drivers looked away for a total of 13 seconds on average, compared with 15 seconds when dialing a contact manually. "The reduction was more substantial for both of the embedded systems, particularly MyLink. The Chevrolet system required an average of 14 seconds of off-road glances for the manual interface and three seconds for the voice interface," IIHS said.

IIHS said drivers using the Chevrolet MyLink system performed less well when entering an address. "Many drivers in the study had trouble getting the system to understand the address correctly or made mistakes as they recited the address in a single string," IIHS said.

But drivers with the Volvo Sensus' menu-based design looked away longer because it required each element of the address to be entered separately and allowed the driver to look at a center-mounted display to verify that the previous component was interpreted correctly.

IIHS said out of 120 attempts to enter an address via MyLink, 38 had system errors, and 23 had user errors. In contrast, there were only five system errors and eight user errors with Sensus. "The one-shot approach of MyLink's voice interface seemed to work well for contact calling, but a full address may be too complicated for that method," says David Kidd, an IIHS senior research scientist and study co-author. "A high error rate could negate some of the benefits of fewer off-road glances. When drivers become frustrated with technology, that itself can be distracting. Or they might give up on the system and resort to another, potentially more distracting navigation method."

The Obama administration has been trying to crack down on distracted driving. In April 2013, the U.S. Transportation Department issued long-delayed guidelines intended to discourage carmakers from installing devices that allow drivers to text from behind the wheel or linger over touch-screens.

In 2013, NHTSA officials found driver behavior with cellphones isn't diminishing significantly, despite state laws. They want to ban drivers from making hand-held and hands-free calls. A 2010 study by IIHS also found that texting bans haven't reduced crashes.

In 2011, the National Transportation Safety Board urged NHTSA to ban nearly all hands-free calls behind the wheel. U.S. Transportation Secretary Anthony Foxx said last year the department will continue to study the issue, but the Obama administration has declined to endorse the NTSB proposal. No state has followed suit either.

The National Highway Traffic Safety Administration estimates that 3,328 people were killed and an estimated 421,000 were injured in distraction-related crashes in 2012.

Currently, 43 states, Washington, D.C., Puerto Rico, Guam, and the U.S. Virgin Islands ban text messaging for drivers of all ages; Michigan is among those states. Separately, 12 states, Washington, D.C., Puerto Rico, Guam, and the U.S. Virgin Islands prohibit drivers of all ages from using hand-held cellphones while driving. Michigan is not one of them. Michigan and 36 other states do ban cellphone use by novice drivers.

In 2013, the number of Michigan drivers who admit they text while driving doubled to 1 in 6, according to a statewide phone survey conducted for the Michigan Office of Highway Safety Planning. A law on Michigan's books since 2010 prohibits drivers from reading, typing or sending text messages while driving. Yet 16.3 percent of drivers who were surveyed admitted to texting and emailing while driving — twice the percentage of 2012.