North American freight volumes bounced back in August from a normal July dip, but it did not lead to a similar increase in freight spending, according to the Cass Freight Index.

August shipment volume increased 2.3%, reversing some of last month’s 3.9% slide. August shipments are 4.9% higher than a year ago and are up 13.9% in 2014.

This happened as other economic measures rose, including the Institute for Supply Management’s August Purchasing Managers Index, increasing 3.3% to the highest level since March 2011. Also, average weekly U.S. rail volume, in terms of carloads plus intermodal containers and trailers, was higher in August 2014 than in any month since October 2007, according to the Association of American Railroads, while the American Trucking Association reported that July truck freight tonnage was up and just 0.6% lower than the all-time high in November 2013.

Meantime, Cass reports the August freight expenditures index dipped 0.3%, as rates remain “stubbornly flat,” according to Rosalyn Wilson, supply chain expert, who provides analysis for the report.

“While capacity was not as tight as expected, and even spot rates weakened a bit during the month, August 2014 expenditures are 8% higher than the corresponding month a year ago and 10.8% higher than December 2013,” she said. “A further increase in freight activity in September as holiday goods begin to flow into to the country will strain capacity. So far, however, that has not been a good indicator of higher expenditures, except on the spot rate markets.”

Wilson noted, as expected, the freight transportation market picked up again in August. “Both imports and exports are trending upward, and new orders are growing in China and Europe. U.S. consumer sentiment continues to climb, signaling a developing belief that the economy will continue to strengthen.”

Another positive sign she said is consumer spending has inched up as the unemployment rate has fallen.

“The recent decline in job creation may be a temporary blip in the data since many industry segments, including construction and manufacturing, are gaining steam again after the seasonal lull from mid-June through July,” Wilson said. “Economic indicators still show hope that the fourth quarter of 2014 may not experience the dramatic drop-off that has come to characterize the economy’s performance since the recession.”

Data in the Cass Freight Index includes all domestic freight modes and is derived from $23 billion in freight transactions processed by Cass annually on behalf of its client base of hundreds of large shippers.