Young drivers navigate better behind vibrating wheel

CARNEGIE MELLON (US) — A vibrating steering wheel that combines audio, visual, and haptic technology may be an effective way to avoid missed turns while keeping the driver’s eyes on the road.

Researchers at Carnegie Mellon University and AT&T Labs tested the steering wheel and found that younger drivers in particular are less distracted by a navigation system’s display screen when they receive haptic feedback from the vibrating steering wheel.

For elder drivers, the haptic feedback reinforces the auditory cues they normally prefer.

Though the haptic steering wheel generally improves driver performance and safety, the findings suggest that simply giving a driver additional sensory inputs isn’t always optimal. That’s particularly the case for older drivers because the additional sensory feedback can strain the brain’s capacity to process it.

“Our findings suggest that, as navigation systems become more elaborate, it would be best to personalize the sensory feedback system based, at least in part, on the driver’s age,” says SeungJun Kim, systems scientist at the Human-Computer Interaction Institute (HCII) at Carnegie Mellon.

The findings will be presented June 21 at the International Conference on Pervasive Computing in Newcastle, England.

Vibrating steering wheels already are used by some car makers to alert drivers to such things as road hazards. But the haptic steering wheel under development by AT&T is capable of unusually nuanced pulsations that can convey more information. Twenty actuators on the rim of the AT&T wheel can be fired in any order. In this study, firing them in a clockwise sequence told a driver to turn right, while a counterclockwise sequence signaled a left turn.

“By using these types of vibration cues, we are taking advantage of what people are already familiar with, making them easier to learn,” explains Kevin A. Li, a researcher with AT&T’s user interface group in Florham Park, NJ.

Kim and scientists at HCII have developed methods for measuring the performance, attentiveness, and cognitive load of drivers that involve a suite of sensors. For this study, they added the experimental AT&T steering wheel to their driving simulator.

Part of a research thrust of the National Science Foundation-sponsored Quality of Life Technology Center, the researchers were particularly interested in learning whether multi-modal feedback would improve the driving performance of elderly drivers. The number of drivers over the age of 65 is rapidly growing; improving the performance of older drivers despite progressive decay in their vision, hearing and general mobility can help maintain their mobility and independence.

Subjects of the new study included 16 drivers ages 16-36 and 17 over the age of 65. In the HCII simulator, people drove a course that included traffic lights, stop signs, and pedestrians while the researchers monitored their heart rate, pupil size, blink rate, brain wave activity, and other measures of attention and cognitive load.

The proportion of time that a driver’s eyes were off of the road was significantly less with the combination of auditory and haptic feedback than with the audio and visual feedback typical of most conventional GPS systems—4 percent less for elder drivers and 9 percent less for younger drivers.

Combining all three modalities—audio, visual, and haptic—significantly reduced eye-off-the-road time for the younger drivers, but not the older drivers. This may have to do with driver preference; self-reports showed older drivers favored audio feedback while younger drivers relied more on visual feedback.

But the researchers also found that combining all three modalities didn’t reduce the cognitive workload of older drivers, a result that was in contrast to younger drivers. Designers of navigation systems for older drivers may need to concentrate on reducing the driver’s cognitive burden rather than resolving issues regarding divided attention.

“We are very excited about the benefits of adding haptic feedback to traditional audio-visual interfaces,” says Anind K. Dey, associate professor in HCII.

“In combination with our ability to measure cognitive load, we can not only design interfaces that people like and make them more efficient, but that also allow them to more easily focus on their task at hand.”

More news from Carnegie Mellon University: www.cmu.edu/news/

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