OKLAHOMA CITY - Oklahoma state troopers are cracking down on some of the worst highway offenders in the last days of summer; tractor-trailer drivers.

In the dog days of August, many take to the highways for one last summer getaway, but more people on the road means more chances for crashes. In fact, the month of August has more fatal crashes than any month out of the year.

Starting Aug. 28, state troopers are looking for 18-wheelers not following the law. It's a part of a nationwide crackdown on Interstate 35 and Interstate 80.

Trooper David Miner has been working the highways of Oklahoma for 17 years. He says one of the biggest issues is sleepiness behind the wheel.

“I’m looking for fatigued drivers and making sure they're in compliance with the federal regulations on hours of service, making sure they're awake and able to drive their vehicle in a safe manner,” Miner said.

According to the National Transportation Safety Board, nearly 40 percent of all crashes involving semi-trucks are because a driver was too tired to be behind the wheel. Miner said it's up to every driver on the road to stay safe.

“People need to realize that a semi is an 80,000 pound vehicle and they need to exercise more caution around semis,” he said.

Drivers are advised to take caution by accounting for speed and stopping distance, putting away distracting devices and watching out for other drivers that may not be watching out for them.

Miner also made a point of saying drivers need to be aware of the mirrors on semi-trucks. He said if a motorist can’t see the mirrors, the driver of the semi can’t see an approaching car, which could potentially lead to a very dangerous situation.