Truck stops are often filled with big-rig drivers taking a break from the road.

And most drivers agree that getting even just a little tired out on the highway is an issue - and a potential problem - that they take very seriously.

"It's a very big concern because probably most of your accidents happen because of just being tired and falling asleep at the wheel," said James Weaver, a truck driver from Oklahoma.

Now, an experimental device may help truck drivers from dozing off behind the wheel. The system uses infrared light to determine when drivers are too tired to be driving.

The Driver Fatigue Monitor measures how "heavy" eyes are becoming by monitoring the eyelids. If the eyes are closed for three or four seconds several times in a minute, then an alarm sounds. Drivers can install the fatigue monitor every time they hit the road.

And some say it may help save lives.

According to the Federal Motor Carrier Safety Administration, 375 people were killed and 7,500 others were injured each year between 1997 and 2000 - all because of accidents caused by tired truck drivers.

One trucker who had not slept in 30 hours caused an accident which left a teenage girl dead. That incident prompted the state of New Jersey to criminalize drowsy driving.

Many drivers agree that using the alarm is well-worth lowering the risk of falling asleep at the wheel.

Driver Roleles Busby, of Dallas, said, "It's a good thing. It's a tool that can be used to implement safety."

Weaver added that an alarm would be very helpful because it could give drivers "enough of a jolt where you can start looking for a place to pull over, because if you are that tired, you need to get off the road."

Richard Grace, the inventor of the monitor, said that's precisely the goal.

"We're not trying to keep him awake. We're giving him information that will encourage him to stop and do the right thing," Grace said.

Other technologies are also being tested to warn truckers of dangerous drowsiness. A device from Assistware Technology sounds an alarm when the truck begins to change lanes erratically.