The Cass Freight Index of U.S. shipping demand grew 12.9 percent in April, according to the measure released Monday, the strongest year-over-year expansion since the global economic downturn took hold.

But Cass Information Systems index of freight shipments also grew a more modest 1.7 percent on a month-to-month basis, signaling the recovery in shipping demand is leveling off.

The index, which had been showing strong acceleration on a month-to-month basis since December, was at its highest point since November 2008, at the start of the recession.

Shipper spending on transportation, based on the Cass index of expenditures, also grew at a 21 percent rate compared to April a year ago, also the strongest year-over-year increase since the downturn.

The expenditures index edged up 1.6 percent in April from March, a sign of stability in transportation rates in domestic shipping.

Source: JOC