By now, those who know me know I’m a driver shortage skeptic. I don’t believe there’s an actual shortage of people who could drive a truck, just a shortage of those willing to drive a truck for the pay and conditions on offer from truckload carriers.

I’ve heard from carrier executives who swear unemployment benefits are keeping truckers from returning to the road, or who blame a lifestyle that doesn’t attract workers who want to spend weekends, and even the odd weeknight, at home.

But pay is at the heart of this issue, and it’s increasingly difficult to ignore it. New data from the Bureau of Labor Statistics underscore why pay is a major contributing factor to the severe difficulty truckload carriers have finding drivers to seat trucks.

The average annual pay for the nation’s 1.51 million tractor-trailer drivers increased 1 percent last year to $39,830, the BLS data show. That’s right, $39,830.

While driver wages increased 1 percent, the inflation rate in 2011 was 2.9 percent, according to the U.S. government, thanks largely to higher energy and food costs. The average overall U.S. wage increased 1.9 percent in the same period.

True, the average is for all types of tractor-trailer drivers, not just long-haul truckload drivers. Average pay in the BLS’s “general freight trucking” subcategory is slightly higher, at $41,250 a year, and grocery drivers averaged $43,900.

But when broken down by percentile, the median tractor-trailer driver wage was $37,930 in 2011, according to the BLS, with half making more, and half less. Only 25 percent made more than $47,130, and only 10 percent more than $58,440.

So when you see a sign on the back of a trailer claiming drivers who haul for that company can make more than $50,000 a year, remember that at least three quarters of all tractor-trailer drivers don’t make that much, and half make much less.

At least those big rig drivers did better than light truck or delivery service drivers, who made $33,120 on average in 2011, according to the BLS. Still, let me know if you think just under $40,000 is fair for the work tractor-trailer drivers do.

I’m thinking especially of those drivers who are out on the road days or weeks at a time. Yes, the $39,830 figure is an average, so some drivers are paid more, and others less. But several truckload carriers tell me it’s right on the money.

Here’s the kicker. That average trucker pay is lower than the overall average U.S. wage, and the gap between them is getting wider. Since 2001, average driver pay has increased 18.2 percent, but the overall average wage is up 33 percent.

In 2002, there was only a 3.4 percent gap between what tractor-trailer drivers were paid, on average, and the national average. Now the U.S. average wage is 12 percent higher, at $45,250, than the average tractor-trailer driver wage of $39,830.

Whether it’s fair or not, that level of pay obviously is not going to attract enough people to meet future freight demand in an industry that moves almost everything sold or purchased in the U.S., especially when the economy grows stronger.

Trucking wages are not only not keeping up with inflation, they’re not keeping up with the prevailing wage in the job market. If carriers are serious about attracting more and better qualified drivers — and keeping them — that must change.

Contact William B. Cassidy at wcassidy@joc.com. Follow him on Twitter at @wbcassidy_joc