Spot truckload freight rates moved slightly lower for the second consecutive week for the seven-day period ending Aug. 19 as freight volume remained strong, according to the freight matching service provider DAT Solutions.

The number of loads posted on its load boards fell 2.1% compared to the previous week while available truck capacity was unchanged. The is due to a seasonal transition, driven largely by produce harvests, according to DAT Analyst Peggy Dorf on the DAT blog.

“Reefers are needed, but anything that affects reefers will affect dry van traffic, as well, so there’s a geographic shift in the van segment,” she wrote. “More loads are available in the Upper Midwest and Northeast, while the Southeast is winding down, and trends in the Western region are mixed.”

Nationally, van load posts fell 1% and truck posts increased 1% to push the van load-to-truck ratio from 4.9 to 1 to 4.8 to 1. The national average van rate fell 1 cent to $1.78 per mile, a small change in an otherwise firm freight market, but down from a four-week high of $1.82 per mile. All reported rates include fuel surcharges.

Refrigerated load posts increased 5% and truck posts declined 2%, which resulted in a 7% increase in the load-to-truck ratio, hitting 9.3 to 1. At $2.07 per mile, the national average reefer rate was 1 cent lower compared to the previous week but is down 5 cents from two weeks earlier.

The Midwest is heating up for reefers, a normal trend for this time of year. More loads are moving out of the Grand Rapids market, and outbound rates rose in Green Bay and Chicago, according to DAT. More loads left Sacramento during the week, but it’s still not a high-volume market at this point in the summer.

Flatbed load posts dropped 7% while truck posts dipped 1%. That caused the load-to-truck ratio to drop to 27.6 loads per truck, still a high load-to-truck ratio for this time of year. The national average rate was 1 cent lower at $2.18 per mile and lower than its four-week high of $2.22 per mile.