An auto manufacturer announced that they were developing a system to track facial cues that indicate that a driver may be falling asleep at the wheel and then use the car's air conditioning system to adjust the temperature and humidity to create an optimal environment to keep the driver awake. The system goes further using aromatherapy to give a blast of aromas designed to increase alertness in the driver. This is just one of several systems in the works to recognize and prevent drowsy driving.

Drowsy driving is a serious issue on America's highways. The National Highway Traffic Safety Administration (NHTSA) reports that, based on police reports there are an average of:

The NHTSA feels these figures fall short of the full amount because they depend on vehicle occupants reporting drowsy driving to the police as a cause factor in the crash.
Studies show that America is a sleep deprived nation with 37% of drivers reporting that they have nodded off or fallen asleep at the wheel, 29% of those within the previous year and 10% within the previous month. That means that up to 75 million drivers have nodded off or fallen asleep at the wheel within the previous month.

With figures like that, the need for some kind of system to alert drivers before they fall asleep becomes apparent however some proposed systems seem to show more promise than others. The system that uses aromatherapy to heighten alertness could have a couple of problems. The system uses a camera trained on the driver and facial recognition software to recognize when a driver starts to yawn. A joint study by the University of California at San Diego (UCSD) and Sabanci University in Turkey found that yawning was ineffective as a predictor because, as someone starts to fall asleep, they yawn less, not more.

Studies designed to measure the effectiveness of aromatherapy have shown that the effect of aromatherapy may be due more to the placebo effect rather than any actual physical effects; that is, the user expects the aroma to work and thus reports a positive effect. A recent study by the University of Ohio looked at the effectiveness of lemon and lavender oils to improve mood. The experiment's subjects were put under a mild stress and then were exposed to cotton balls soaked in lemon oil, lavender oil, and water as a control. Some subjects were "primed" by being told what odor to expect while others were not. The results showed that the subjects, when told what aroma to expect, reported an improved mood more often after they were exposed to the water soaked cotton balls than the ones soaked in lavender oil. Blood pressure and blood chemical tests taken before and after exposure, showed no significant change in blood pressure or mood elevating chemicals.

In a German study designed to test aromatherapy's ability to increase alertness subjects were given cognitive tests before and after exposure to aromatic oils. A control group was tested without exposure to the oils. The study showed no statistical difference between those exposed to aromas and the control group.

Other systems that are under development to detect drowsiness in a driver show a little more promise. The UCSD program looked beyond yawning as a predictor for drowsiness. This program looked at 45 different points on the face. The study found that there were many more facial cues such as raised eyebrows, as the subjects fought to keep their eyes open, increased eye blinking, and other cues. The facial recognition software is designed to recognize all of those facial cues to predict that a driver may be drowsy. Different facial cues, along with erratic steering inputs, seem to show the best promise as a predictor for drowsy driving.

Mercedes has spent ten years developing a system that uses multiple cues and then sounds an audible alarm along with a flashing coffee cup icon on the dashboard display to warn the driver that he or she may be falling asleep.

These systems show some promise in their ability to warn a driver but the danger in these systems come when drivers depend on the system to give adequate warning instead of getting plenty of rest before hitting the road. A number of technological advances have been developed to make driving safer but safety experts warn that drivers may tend to rely too heavily on the technology rather than their own responsibility to be rested, alert, and paying attention to the driving environment ahead and around them. No matter how good the technology, it is still the driver's responsibility to be in full control of the vehicle.