Advanced user interfaces take safety into account: Part 1 - Distractions and helpful HMIsEdited by Rick DeMeis
A war is being waged in the modern vehicle interior. On one side, there is growing demand for graphically compelling, media-rich automotive electronics that offer connectivity to personal devices, location-based services, and the Internet. On the other side, there is growing concern about driver distraction and vehicle safety. But properly designed, the vehicle's human machine interface (HMI) can act as a bridge between these opposing factions, allowing the driver to enjoy increased connectivity while remaining focused on the task at handdriving.
In fact, a well-designed HMI can actually assist the driver, providing information in a way that helps he or she keep his or her eyes on the road and hands on the wheel. To achieve this balance, HMI designers can leverage an ever-growing arsenal of technologies, including LCD displays, touchscreens, voice recognition, audio feedback, command structure, dialogs, and graphical "widgets."
What constitutes driver distraction? "Distraction occurs when a driver is delayed in the recognition of the necessary information to safely maintain the lateral and longitudinal control of the vehicle due to some event, activity, object, or person, within or outside the vehicle that compels or tends to induce the driver's shifting attention away from fundamental driving tasks."Ref. 1
Without question, driver distraction contributes to a huge number of vehicle accidents.Ref. 1, 2 The U.S. National Highway Traffic Safety Administration (NHTSA) estimates that at least 25% of crashes involve driver distractionRef. 3, the Victorian Road Safety Commission in Australia puts the number at between 20% and 50%,Ref. 4 and Transport Canada, at least 20%.Ref. 5 The most comprehensive study to date, the NHTSA 100-Car Naturalistic Study,Ref. 6 found driver inattentiveness to be a factor in 78% of crashes and 65% of near crashes. This study measured the effects of cell phones, PDAs, and other similar distractions as well as nonelectronic distractions such as smoking, eating, daydreaming, personal grooming, and conversing with passengers.
In response to such studies, many government agencies are outlawing the use of cell phones in the vehicle. Fifty countries have instituted some form of ban, some mandating jail time for offenses. In the US, twenty states have imposed either a complete ban or a partial ban based on age or other circumstances. Of these worldwide bans, only three impose controls on the use of hands-free kits, and two of these apply only to teenage drivers.Ref. 7 Everyone recognizes the value of a phone in the vehicle, and the removal of that privilege isn't taken lightly.
Some jurisdictions allow hands-free, but not hand-held, cell phone use because of the perceived difficulty of operating a phone while driving.Ref. 8 Nonetheless, hands-free systems don't alleviate our brains of the cognitive processing required to carry on a conversation. One study by Strayer, Drews, and Johnston,Ref. 9 designed to test this hypothesis, reports that, "the interference from [hands-free] cell phone use was obtained despite the fact that there was no manual manipulation of the phone during the dual-task portions of the experiments." Preliminary studies done by QNX Software Systems indicate that less intelligible speech during a hands-free call imposes a higher cognitive load, suggesting that improved call quality can reduce distraction.
Our society is currently willing to embrace other cognitive loads for the driver, such as listening to music or conversing with passengers, which could also contribute to distraction. Studies show that visual-manual tasks, such as taking your eyes off the road to turn a radio dial, create significantly greater distractions than purely auditory-vocal tasks.Ref. 10 Unfortunately, no standard accepted method of measuring driver distraction currently exists.