NEW YORK, April 7 - Ford announced today results of a comprehensive five month study into the deadly problem of drowsy driving, and gave a preview of new Volvo-developed safety technology to be introduced late in the decade.
"We have been able to demonstrate that we have the ability to alert a drowsy driver to a lane departure and improve their performance," said Jeff Greenberg, staff technical specialist, Vehicle Design Research, Ford Research and Advanced Engineering. "We are confident that we can do it in ways that drivers will accept. The new system will be adaptive and intelligent - to sense true driver status."
Since November, more than 30 drivers have taken part in the development effort, where they literally fell asleep behind the wheel of the VIRTTEX driver simulator.
VIRTTEX stands for VIRtual Test Track EXperiment. Ford is the only North American automaker with a full-motion-based driving simulator like VIRTTEX. It allows Ford researchers to test product features and driver behaviors safely in a controlled environment.
A Deadly Problem
According to U.S. National Highway Traffic Safety Administration (NHTSA) estimates, drowsiness accounts for about four percent of all fatal crashes - more than 1,500 deaths each year. It is a major cause of catastrophic accident and injury. It is estimated that approximately 100,000 police-reported crashes annually - about 1.5 percent of all crashes - involve drowsiness and fatigue as a principal causal factor.
"These are often not minor accidents when they occur," said Greenberg, who runs the VIRTTEX lab. "When someone falls asleep at the wheel, the vehicle often leaves the lane and the roadway - followed by a major crash or rollover."
According to the National Sleep Foundation (NSF) 2002 Sleep in America poll, about one-half of adult drivers - 51 percent or about 100 million people -- say they have driven a vehicle while feeling drowsy in the past year, and almost two in 10, (17 percent or 32 million people), have actually fallen asleep at the wheel. One percent (approximately two million drivers) admit they have had an accident because they dozed off or were too tired to drive.
Study Results
The Ford/Volvo driver drowsiness study using VIRTTEX is the most complete controlled laboratory study ever conducted into this issue - it tested more subjects over a longer simulated drive. It was a continuation of many years of driver drowsiness research conducted by Volvo.
"A National Highway Safety Administration survey found that on average, drivers are on the road for almost three hours before they nod off," said Ksenia Kozak, technical expert in biomechanics and human factors, Ford Research and Advanced Engineering. "So our three hour simulator drive recreates conditions under which drivers are likely to fall asleep. We focused on driver-initiated lane departures in the final hour of our simulator drive." Volvo researchers developed the technology to be tested, determined how it would function, and set the test requirements, in conjunction with the VIRTTEX team at Ford.
A total of 32 test subjects took part in the study (one each morning, up to four a week) starting Nov. 4, with the study concluding March 10. Ages of participants ranged from 24 to 69 years. A total of 12 men took part, and 20 women.
More than 300 potential test subjects were interviewed with a detailed 15-page questionnaire. Researchers were looking for a varied group of men and women that represented likely Volvo customers in terms of income and vehicle desire. Test participants were asked to stay up all night, the night before the test, and to take no caffeine after six p.m. that preceding evening. A sensor placed on a watchstrap is worn the day before the test to verify that the test subject does not fall asleep.
Performing the Tests
Early the following morning, after a sleepless night, the test subject is driven to the Ford Scientific Research Laboratories. At six a.m. the test subject enters the VIRTTEX simulator and then drives for up to three hours on a simulated darkened country road.
Starting the test, seven subjects were rated alert, 10 were moderately drowsy, and 15 were rated very drowsy.
Three subjects drove off the road and "crashed." Two subjects requested to have the experiment end. Observed behaviors in an effort to remain awake included: changing posture/fidgeting, singing, playing with the CD player (changing the song, turning up the volume), slapping their face, drinking water, and actively looking at the outside environment.
Moses Fridman was one of 18 test participants who took part in pre-trial drives in VIRTTEX. A Ford powertrain engineer, he was recruited to take the test through an ad on a Ford internal website (All of the actual test participants were non-Ford employees). He says going without coffee and caffeine was difficult as he stayed awake the night before by taking walks and going on the internet. "But the real difficulty in staying awake began when I slipped behind the wheel of VIRTTEX -- the road was long, dark, straight and monotonous," Fridman said.
"The test was very realistic," Fridman added. "After you began moving, your subconscious tells you it's real. VIRTTEX is a powerful research tool, and after being a participant in this test, I think this lane departure warning technology being developed will work - it will save lives. I wish I had it on my own car."
Although the test was designed to study the effects of warnings and not the differences between age groups -- it is interesting to note that the youngest drivers did the worst in the test. The two youngest test subjects, a 24 and a 26 year old man, actually fell asleep and ran off the road.
It was middle age women between 45 and 60 years of age who did best - having the least problems, and fewest episodes of dozing behind the wheel.
What Happens When You Fall Asleep Behind The Wheel
The research indicated that falling asleep behind the wheel was episodic - it came in brief intervals during the drive. These "micro-sleeps" ranged in duration from a half second to ten seconds. The average time span was about two and a half seconds - before the driver would return to a baseline of consciousness until drifting back into the micro-sleep state again.
"When a vehicle is traveling at 70 miles per hour, you are covering more than 100 feet in just one second. If you are asleep, you are putting yourself and others on the highway at great peril," Greenberg said. "Some participants who fell asleep at the wheel, when told that they were out for several seconds were shocked, and said it felt more like a fraction of a second."
The purpose of the new technology under development is to combat these lapses, until a tired driver can get off the road and get some rest.
What Worked - and What Didn't
Ford researchers looked at several different technologies to sense a driver falling asleep, a lane departure, and to alert them and get them back into their lane.
In September, a Ford Taurus (which had starred in an earlier breakthrough driver distraction study) was moved out of the VIRTTEX test chamber, and a Volvo S80 was moved in.
A camera worn on a headset, and pointed at the driver's left eye, monitors eye movement. A computer calculates the percentage of eye closed versus eye open - to sense if the driver is falling asleep.
When a lane departure is sensed, the sound of running over highway rumble strips could be broadcast to the driver, or a heads up display could flash red led lights on the windshield, or the steering wheel could be vibrated. The steering wheel could also be forcibly turned to keep the vehicle in the lane. "What we discovered," said Greenberg, "is that not every technology that helps combat drowsy driving is tolerated or well-liked by drivers. False alerts are considered annoying and could nag the driver to the point he or she just turns the system off. And a system that is turned off is not serving any purpose whatsoever."
Breaks in driving - such as a stop to go to the rest room or for a quick walk - did not seem to have much effect on combating driver drowsiness during the test. Drivers soon reverted to their drowsy state and would soon fall back asleep. "Nothing beats getting some sleep - either for 30 minutes, or better yet, a few hours," said Greenberg.
Volvo First to Get New Technology
The new safety technology developed through this research will offered first on Volvo cars and SUVs late in the decade - and then possibly later on other Ford Motor Company brands.
"This new drowsy driver and lane departure technology will be one more advancement in Volvo's long history of innovation in the field of automotive safety, said Robert Hansson, manager, Vehicle Controls, Volvo Cars. "In this development effort, the VIRTTEX simulator was a great tool to test driver behavior efficiently, adequately and safely, providing important help in the evaluation of alternative technologies in order to come to grips with the drowsiness issue."