SAN ANTONIO -- Department of Public Safety inspector Wayne Kenney waves his hands like an air-traffic controller, guiding hulking 18-wheelers through a roadside weigh station.

His voice is barely audible through the roaring of engines.

According to Kenney, about 2,500 trucks will pull through this weigh station every day. Part of his job is to make sure they’re safe.

“We'll probably inspect around 25 to 35 trucks a day,” Kenney said.

The inspections are like those at an airport. All the trucks will go through automated sensors that can detect certain things – a flat tire or a faulty axle. The electronic systems also allow inspectors to view driver logs, including how many hours they’ve been driving and what they’re carrying for cargo.

“They’re tools that can help us,” Kenney said. “They’re not all conclusive, it takes the man-power to actually stop a truck and inspect it.”

Because they can’t inspect every truck, those inspections are done at random according to federal requirements.

And Kenney says they know exactly where to look first.

"The one big thing we're looking for is brakes,” Kenney noted. “If you're the car in front of this truck and you throw on the brakes, you better hope he's got 10 working brakes. That's what you're after."

It’s an ideal scenario Kenney says almost never happens.

"They'll always have problems somewhere,” Kenney said. “You’ll have brakes that simply don’t work, they don’t move, there’s no motion to them.”

In a given day, Kenney says he’ll have to remove two or three trucks from the roads, usually cases where multiple brakes are worn or completely shot.

That’s a rate of up to one in every 10 trucks.

According to TxDOT, commercial vehicles were involved in 1,992 accidents in Bexar County in 2016. Of those, 16 were fatal and 34 involved incapacitating injuries.

Nationwide statistics from the Federal Motor Carrier Safety Administration show fatal accidents spiked by a fifth between 2009 and 2013, then took a dip of about 5 percent between 2013 and 2014. Injuries consistently skyrocketed by 55 percent between 2009 and 2013, while property damage also increased by nearly a third.

Jeff Miller, a life-long trucker and driving instructor at Southern Career Institute, says he has a good idea why.

"Driver error, whether that's driver fatigue or, nowadays, driver inattentiveness,” Miller said.

Miller noted that fatigue is less common now, as electronic logs make it almost impossible for drivers to exceed the maximum amount of road hours allowed by law. But he said that pre-trip inspections can and do get neglected, meaning drivers often miss things like faulty brakes.

"A lot of things can go wrong in a short amount of time in these trucks,” Miller said. "By the time you notice a brake pad has gone bad, it's too late."

But Miller pointed out that the fault isn’t always on the truck driver. Drivers of what he calls "four-wheelers," or standard cars, are often oblivious to what’s going on when they pass a truck.

For example, trucks are made to brake and handle best with a full 80,000-pound load. A truck that’s carrying a partial or empty load will take about 40 percent longer to stop – the difference between two football fields and two-and-a-half.

Blind spots, he says, are also a major concern.

His advice is to give trucks as wide a berth as possible and to be prepared for the unexpected. Nothing that big and fast, he says, is ever idiot-proof.

"Nine times out of 10, you run into a truck, the truck will win,” Miller said. “It's just physics."