The annualized truck driver turnover rate at the nation's big truckload fleets surged in the second quarter to 106 percent, the American Trucking Associations (ATA) said today. The increase marks the first time since the fourth quarter of 2007 that driver turnover has reached that level.

The last time the turnover rate for large fleets—defined by ATA as carriers with an annual revenue of more than $30 million—surpassed 100 percent was in the first quarter of 2008, according to the trade group.

For smaller truckload fleets, the pace of the second-quarter turnover was extraordinary. Turnover soared to 86 percent, a 15-percentage-point jump from the first quarter of the year and the highest level in five years, ATA said.

Driver turnover at less-than-truckload (LTL) fleets, by contrast, averaged just 9 percent in the second quarter, ATA said. Turnover in the LTL segment is generally much lower than in the truckload sector because LTL drivers are usually better paid and operate over shorter routes, which allow them more time at home and a better work-life balance.

The ATA figures lend credence to the long-held belief that, in the current environment, retaining qualified drivers is as difficult—if not more so—as recruiting them.

Bob Costello, ATA's chief economist, said good drivers are enjoying a seller's market of sorts as newly implemented government safety programs like CSA 2010 force marginal and subpar drivers out of the business and increase demand for drivers with clean safety records.

Costello added that current volume growth—albeit sluggish—is increasing demand for drivers in general, and high-quality drivers are more emboldened to jump employers for better pay and for what they perceive as improved working conditions.

In a statement, Costello estimated that the industry is short between 20,000 and 30,000 drivers. That is well below other estimates—such as those from Noel Perry, founder of the consultancy Transport Fundamentals—of a current shortage of 100,000 drivers.

Costello said the current shortage reflects a dearth of qualified drivers rather than a lack of drivers in general. He added, however, that shortages will become more widespread as freight traffic continues to grow, thus "exacerbating the qualitative shortage and creating a quantitative one."