Study: Tactile Signals Can Give Directions to Drivers

Two devices, mounted on the steering wheel of a driving simulator, convey navigation information -- turn left or turn right -- to the driver. (Nate Medeiros-Ward, University of Utah)

A new study finds drivers talking on cell phones and not hearing spoken instructions from a passenger or navigation system, can still get directions from devices mounted on the steering wheel. Nate Medeiros-Ward, a psychology doctoral student at University of Utah in Salt Lake City will present the findings tomorrow at the annual meeting of the Human Factors and Ergonomics Society in San Francisco.

The study was a collaboration between the university’s psychology and engineering departments. William Provancher, an assistant professor of mechanical engineering co-authored the study with Medeiros-Ward, along with David Strayer, professor of psychology, Joel Cooper, who earned his psychology Ph.D. at University of Utah and now works in Texas, and Andrew Doxon, a Utah doctoral student in mechanical engineering.

The research was based on a “multiple resource model” of how people process information, in which resources are senses such as vision, hearing and touch that provide information to the brain. The study was conducted on a driving simulator that Strayer has used to demonstrate the hazards of driving while talking or texting on a cell phone. Two devices built by Provancher to convey information by touch were attached to the simulator’s steering wheel so one came in contact with the index finger on each of the driver’s hands.

During driving, each index fingertip rested on a red TrackPoint cap from a ThinkPad computer — those little things that look like the eraser on the end of a pencil. When the drivers were supposed to turn left, the two touch devices gently stretched the skin of the fingertips to the left (counter clockwise); when a right turn was directed, the TrackPoint tugged the skin of the fingertips to the right (clockwise).

Nineteen University of Utah undergraduate students – six women and 13 men – participated in the study by driving the simulator. Four driving scenarios were used, each lasting six minutes and including, in random order, 12 signals to the driver to move to the right lane and 12 more to move left.

The results:
– In two scenarios without cell phones, the drivers’ accuracy in correctly moving left or right was nearly identical for those who received tactile directions through their fingertips (97.2 percent) or by computerized voice (97.6 percent).
– That changed when the drivers talked on cell phones while operating the simulator. When drivers received fingertip navigation directions while talking, they were accurate 98 percent of the time, but when they received audio cues to turn right or left while talking on a cell phone, they changed lanes correctly only 74 percent of the time.

The researchers say they don’t want their results to encourage dangerous and distracted driving by cell phone users. Instead, they hope the study will point to new touch-based directional devices to help motorists and hearing-impaired people drive more safely. The same technology also could help blind pedestrians with a cane that provides directional cues to the person’s thumb.

Provancher has patents and wants to commercialize his tactile feedback devices for steering wheels and other potential uses.