The annualized turnover rate at large truckload carriers rose 13 points to 100% in the third quarter of 2015, the highest it has been in three years, according to Bob Costello, chief economist for the American Trucking Associatons.

However, during the same period, the turnover rate fell to 68% for smaller truckload carriers. That matched the lowest point since 2011.

“It is just one data point, so it is hard to draw any real conclusions on what is happening with turnover,” said Costello. “However, the increase in the turnover rate at large carriers matches up with what we’ve been hearing anecdotally from fleets: that the market for drivers continues to be tight.”

For the first three quarters of 2015, fleets with more than $30 million in annual revenue averaged 90% turnover which is actually down slightly from 2014’s 95% average. Small carriers have averaged a rate of 75% year to date, which was a significant drop from 90% in 2014.

Less-than-truckload fleets dipped three points to 10% in the third quarter of 2015 and averaged 10% for 2015 so far based on available statistics. This is down 1% from 2014.

“The split in the truckload turnover rates is not unusual, but may be caused by a variety and combination of factors,” said Costello. “We may likely have a clearer picture of the driver market once fourth quarter turnover figures are in so we can better analyze any possible trend.”