SAVANNAH — Tribe Transportation is a growing company that just added 10 new trucks to its tractor-trailer fleet. The problem has been hiring people to drive them.

So far the Georgia-based company has filled four of the jobs, leaving six vacancies. The new hires are mostly veteran truckers in their 50s, men who probably won't spend too many more years behind the wheel, said Matt Handte, Tribe's executive vice president for sales and operations,

"It blows my mind that I'm looking for that many people and I can't find them," said Handte, who's also struggling to hire logistics brokers who line up freight transportation for customers such as PepsiCo, H.J. Heinze Co. and General Mills. "They aren't lined up at the door."

Even amid a struggling economy with high unemployment, trucking companies had a tough time hiring young drivers willing to hit the road for long hauls. Now the U.S. is speeding toward a critical shortage of truck drivers in the next few years as the economy recovers and demand for goods increases, an expert in the inner-workings of supply chains said in a report Tuesday.

U.S. companies are expected to create more than 115,000 truck driver jobs per year through 2016, but the number of Americans getting trained to fill those jobs each year is barely 10 percent of the total demand, said Page Siplon, executive director of the Georgia Center of Innovation for Logistics.

"Trucking accounts for how we move 80 percent of cargo in our nation" said Siplon, whose center is part of the Georgia Department of Economic Development. "If we don't have enough workers, it's going to be slower and more costly to move products. If I can't move as much product to the shelves as I want to, the cost to consumers goes up."

Siplon looked at a range of supply-chain jobs — from truck drivers and warehouse workers to air cargo supervisors — using career-specific employment forecasts by the U.S. Department of Labor and then comparing those numbers with Education Department statistics showing how many degrees and certifications for those jobs are being earned each year.

The results found truck drivers will account for 43 percent of expected growth in logistics jobs, but those will also be the positions with the fewest workers trained to fill them.

That doesn't surprise Tom Pronk, vice president of recruiting for C.R. England, a Salt Lake City, Utah-based company that employs 7,500 truck drivers who deliver foods from companies such as Hershey, Nestle, ConAgra and Coca-Cola to retailers.

"We have an endless need basically in the industry," Pronk said. "Everybody I talk to is very thirsty for drivers. My personal opinion is it's only going to get worse before it gets better."

Truck drivers make decent money. The Department of Labor says the median yearly wage for tractor-trailer drivers is $37,770, with some drivers earning more than $57,000. Handte and Pronk both said some drivers can clear $100,000 a year.

Both men said older drivers are feeling pressured to retire by federal safety regulations enacted in 2010 that keep a closer watch on drivers' work hours, drug testing any tickets and traffic citations they get on the job. And the job can be hard to sell to younger workers who don't think it's worth the money to spend days and weeks on the road away from their families.

"For our new generation who's coming into the industry, the job is not as romantic to them as it was to their predecessors," Pronk said. "It's a tough job to be an on-the-road trucker."

Truck drivers don't need college degrees but they do need to earn a commercial driver's license. That can take a month or longer of taking classes that cost $3,000 or more.

Trucking companies are trying different approaches to lure young drivers into their rigs. Some offer higher wages — a few extra cents per mile — or work with their drivers to carve our shorter routes designed to get them home sooner. C.R. England, which operates five driver training schools in the U.S., is refunding tuition to graduates after they work six months for the company.

David Sheehy of Greely, Colo., just graduated from the company's school in Salt Lake City. He'll be paired with an experienced driver for the next month, perhaps longer, before hitting the road on his own.

Sheehy, 32, said economic hardships in his hometown pushed him toward trucking after years of bouncing between different jobs with little stability. He drove a tow truck, worked for a car rental company and even was an umpire calling little league and high school baseball games. He's single and excited about seeing new parts of the country. And he's eager to earn steady pay.

"It is truly a special breed," Sheehy said. "You're talking about long hours, weeks on the road at a time, time away from family. There are a lot of negative things.

"But they told me a first-year driver can gross $40,000 a year easily," he said. "You're taking about financial security there."