Although many questions remain about this particular crash, including whether the truck driver had actually dozed off at the wheel, we do know driver fatigue plays a part in up to 7,500 fatal motor vehicle crashes a year
in the United States. It is estimated to be involved in 25% of all fatal collisions of this type, according to the Centers for Disease Control and Prevention.
"It's clearly a significant problem and it's rampant," said Daniel Blower, associate research scientist at the University of Michigan Transportation Research Institute.
"It has always been a problem, but my hunch is that (drowsy driving) has probably increased," Blower said.
However, these numbers could start coming down as technologies, such as forward collision warning systems, are being introduced both in delivery trucks and personal vehicles.
Who is the typical drowsy driver?
It is more common for people to fall asleep while driving if they tend to sleep six hours or less a night
, or snore ,or if they unintentionally doze off during the day. In general, accidents related to drowsy driving often take place at night and on higher speed roads such as interstates, Blower said.
In Tracy's crash, a Wal-Mart truck driver, named Kevin Roper, rear-ended the limo on a New Jersey turnpike in the early morning hours. Roper was going 65 mph and did not slow down to the posted 45 mph as he entered a construction zone where the crash took place. The government investigation determined the collision could have been prevented if he were going 45 mph
However, as Blower pointed out, truck drivers are not any more prone to drowsy driving than a person driving home after work, and maybe a night out with friends.
"One often hears it's specifically a truck driver problem and I think it's a broader social problem," he said. Yet accidents involving trucks do tend to be more serious because they are bigger than personal vehicles, he added.
Drowsy driving as dangerous as drunk driving
The National Highway Traffic Safety Administration estimates that about 2.5% of fatal, and 2% of nonfatal
motor accidents are related to driver fatigue. And experts believe these numbers are a vast underestimate of the actual impact of drowsy driving. Fatigue is often not noted on police reports in many cases, partly because it can be hard to spot, Blower said. There is no test for sleepiness like there is for drunk driving.
Instead, the number of deadly crashes that are due to sleepiness is probably closer to the CDC's estimate of 25%, Blower said. However, fatigue probably plays less of a role in nonfatal accidents, he said.
Drowsiness impairs drivers in many ways.
It makes them less attentive, impairs judgment and slows reaction time. And the severity of these impacts varies. For example, if you are only a little tired you might zone out and be slightly less aware of your surroundings. On the other hand, if you are exhausted and fall asleep at the wheel, you have no awareness.
Data suggest that crashes involving drowsiness and intoxication are more severe than the average accident, Blower said. Drivers under the influence of fatigue or alcohol tend to go off the road and roll over, and don't usually do anything to avoid the accident, such as braking or steering, he said.
Studies show that people who have been awake for 24 hours have the same level of cognitive deficits as those with a blood-alcohol level of 0.10%
, which is above the legal limit in most states.
A little help from technology
Many large companies are starting to use delivery trucks with built-in systems to help prevent collisions, Blower said. It is unclear if the truck involved in Tracy Morgan's crash had this technology.
The most common system is forward collision warning, in which cameras or lasers detect objects in the driver's path and compute time to collision. These systems alert the driver by beeping, flashing light, and in some cases even braking for the driver.
A growing number of car companies, including Chevrolet and Mazda, offer these systems in their cars
. Research suggests that these systems can reduce rear-end accidents by about 10%
Among the newer technologies are lane and road departure warning systems, which detects when drivers are about to cross a lane line and emits a warning tone. Studies have found that these systems can reduce the rate of drivers going off the road
by about 40%.
and BMW vehicles use the driver's steering adjustments to gauge drowsiness. If the driver starts steering less, which can happen because of fatigue, he gets an alert in the form of a beep or a flashing sign on the dashboard, said Blower, who has studied collision avoidance technologies for companies such as Volvo. Although these newer technologies tend to be in higher end vehicles, the technology will probably trickle down, he said.
In addition to systems that come built into cars, there are gadgets and phone apps that could help keep a tired driver safe. One is the driver fatigue alarm
that fits into the ear and beeps or vibrates when it senses the telltale nodding of a sleepy head. Another device called Vigo
, which is in development, is a Bluetooth headset that warns wearers if they are sleepy based on their pattern of blinking and body movement.
The Anti Sleep Pilot
is a device for the dashboard and is also available as a mobile app for the iPhone or iPad. It gauges the user's level of fatigue based on factors such as age, weight and average amount of sleep a night. If it decides you are likely to be sleepy, it tries to revive you by intermittently asking you to touch the device. Other apps
try could make it harder for you to snooze at the wheel by asking you trivia questions or making alarm clock noises at regular time intervals.
There are also steps that drivers themselves can take to reduce drowsiness, including drinking a coffee and taking a 15-minute nap, Blower said. But if you do feel sleepy, "the point is: Don't put yourself in that position in the first place because the consequences are just so severe," he said.