Truckload freight volumes increased in March although ample capacity and weather-related supply chain disruptions kept rates in check, said DAT Solutions, which operates the largest truckload freight marketplace in North America.

The DAT Freight Index increased 4.3% in March compared to February. The index is a monthly volume indicator for full-truckload van, refrigerated and flatbed freight transportation.

“We anticipated a bigger increase in demand for trucking services, but unexpected events, including flooding in the Midwest and a major tank fire in Houston, prevented the typical surge of shipments ahead of the close of Q1,” said DAT Senior Industry Analyst Mark Montague. “As a result, truckload rates were lower than expected in March.”