But just how many trucks are rolling down state highways with significant safety problems is anybody's guess. According to data obtained by ABC11 from the NC Highway Patrol, 9.3 million trucks came through state weigh stations in 2009, but less than one percent of them got safety inspections.
The I-Team recently watched at the Hillsborough weigh station as troopers inspected trucks driving toward the Triangle.
While we were there, three trucks were pulled off the road for problems that included nearly bald tires and a cracked wheel rim. Another trucker was cited because his load was not secure. Wooden pallets were in danger of flying off and landing in the highway or on another vehicle.
"It's always a different violation or crack in the frame or maybe several brakes out of adjustment or maybe a guy's found a way to falsify a log I've never seen before," Trooper Travis Ingold explained.
But while the trucks we saw were of concern, they're likely just the tip of the iceberg. Troopers say they individually average only about 25 inspections per week.
"That's a tiny fraction of the trucks driving by you," pointed out investigative reporter Steve Daniels.
"Yes sir," Ingold responded.
"There could be trucks who have no business being out here driving right by us right now," said Daniels.
"That's right," said Ingold.
Unlike some states that keep weigh stations open 24 hours a day, in North Carolina they're generally open 16 hours a day 5 days a week, and we discovered that many times there are no troopers on duty to do inspections.
"It's the manpower we have," said Ingold. "We need more troopers. We need more of us that are certified inspectors."
Troopers say they're trying to do what they can with the resources they have.
"We are trying to open these weigh stations more hours of the day, more times of the week, and try to catch vehicles and drivers off guard and do what we can to ensure the safety of the public," explained Major Marc Nichols with the NC Highway Patrol.
Nichols runs the truck safety program for the state.
"We don't have enough troopers to inspect every truck, but that's not the point. We have to be better planners and managers. We have to inspect the vehicles as we see needed," he said. "Not all vehicles have to be stopped or inspected. So, we're trying to stop vehicles that we feel like could cause a possibility of a safety defect on it or the driver error."
Not every truck on the road is a potential safety problem and many truckers take pride in being safe.
"It's my job to keep this truck safe so you can drive down the road and not get run over by trucks that has no brakes," trucker Christopher Lowry told ABC11.
The North Carolina Trucking Association says safety is a big concern for it too. It works hand in hand with the Highway Patrol and has won several national awards for its commitment to safety and training programs.
And not every crash is a truck driver's fault. Trucks are large and take longer to stop than cars. So if a car driver darts in front of a big-rig, the truck driver may not be able to stop. Trucks also need wider turning radiuses than cars, and a car driver who cuts inside may cause an accident. Truck drivers must also contend with blind spots that make it hard to see smaller vehicles that sit in them.
Still, troopers say poor maintenance on semi trucks is a significant problem and they know how important their jobs are.
"When we know that we've done an inspection and put a vehicle out of service and we see something that was getting ready to be a catastrophe … then we know we've saved a life that day," offered Sgt. Dean Edwards.
Edwards is trying to prevent the pain and heartache Beverly and Jim Harrell have endured. They lost their 21-year-old son Doug to a big-rig along Highway 13 in Goldsboro.
"He was just a joy to be around. He made everybody feel like they were special," said Beverly Harrell.
Doug was riding his bike home from his cousin's house down the road when a speeding trucker - who had been on the job for 23-hours - plowed into him. The Harrell's lawyer says the trucking company consistently had many of its drivers violate the legal number of hours they're allowed on the road.
"They were playing Russian roulette because it was a matter of time. Somebody was going to end up killing someone," said Beverly Harrell.
Driver fatigue as a result of too many hours on the road is another major cause of highway accidents.