A study by the Insurance Institute for Highway Safety (IIHS) finds that simplified voice-command systems help older drivers pay attention to what's happening on the road.
The IIHS tested the impact on drivers ages 20 to 66 of audio-based and button-and-knob-based command systems for making phone calls. It concluded that voice-command systems are more likely to keep drivers’ eyes on the road.
While voice-command systems do help, the older drivers get, the more prone they are to lose focus.
“In general, as age increased, drivers took longer to complete phone calls and made more off-road glances lasting longer than two seconds when placing calls,” the IIHS found. “For example, for every 10-year increase in age, drivers took 3.7 seconds longer to make phone calls, and the percentage of long glances away from the road increased 0.4 percentage points. Older drivers also made more errors when using the different systems.”
However, the IIHS found that when a voice-command system is simplified, the age-related decreases in attention can be eliminated. Using a system that requires only a single detailed command rather than multiple statements, older drivers show as much focus as younger ones.
Ian Reagan, a senior research scientist for IIHS and coauthor of three papers based on the study, said the results show that “single-command voice interface design” may keep drivers of all ages better focused than alternative methods.