Rising diesel prices are forcing some truck drivers to hit the brakes.

Filling up their big rigs these days comes at a big cost. According to AAA, Pennsylvania's average for diesel fuel is $4.15 a gallon.

"They're killing us. It's too expensive," said Leo Bonilla, a truck driver from Easton. "We don't have enough to pay for it."

"You need to pick the money where it needs to go or you won't be here," said Gene Mullen, a truck driver from McAdoo, Schuylkill Co.

Bonilla and Mullen are owners of truck moving companies who said that many once privately owned truck companies are now being bought by bigger companies because it is too expensive to foot the bill for fuel.

"That's why everyone is going out of business," said Mullen, who noted that a truck that holds about 200 gallons of fuel costs truckers more than $700 to fill.

Both men said they calculate a fuel surcharge each month, but gas prices are rising so fast it's hard to keep up.

"We'll probably have to stop those trucks all together because we can't afford it anymore," said Bonilla.

The national average of diesel is currently $3.95 a gallon. That's up 39 cents since last year. That might not seem like a lot of money to some, but for truck drivers, those prices can make or break their business.

"When I fill up, it's about $800. It lasts me about three days, four days. It's been about over a thousand dollars a week," said Bonilla.

"You just got to make sure you get enough money per mile to run the truck or you're wasting your time," said Mullen.

During the height of the recession, Mullen said he remembers diesel fuel being more than $5.00 a gallon, something he hopes to never see again.