You may know that truck drivers work long hours, but did you know that regulations restrict how long and how much they can work at one time, in order to help prevent drowsy-driving collisions? Drowsy driving is a major concern for truck drivers and the companies that hire them. Sleep deprivation can make a person just as dangerous on the road as drunk drivers are.

While there are short term interventions, like drinking coffee or energy drinks, taking brief 20-minute catnaps or getting out and walking around for a few minutes, the reality is that someone who is sleep-deprived is going to get tired again until they get the rest they need.

One step that many states have implemented to help prevent crashes caused by drowsy truck drivers is the use of rumble strips. You may be familiar with these strips found on the outer edges of the lane. A rumble strip has one important job: To cause noise and vibration if the wheels if the vehicle touch them.

This vibration, if you’ve ever felt it, is pretty strong. The sound can also alert drivers, depending on the depth and size of the strip. That’s an intentional design element, because the louder the strip and the more vibration it causes, the better the chances are that the driver will wake up.

If a driver goes off the road, they could end up rolling, jackknifing or colliding with other motorists or pedestrians. This road feature may help prevent crashes, but it’s still important for drivers to get enough sleep. If you see a truck driver acting recklessly, report them. At the very least, the police can get them off the road.