In a year of a record amount of freight on the spot market, March was no exception with freight availability increasing 56% in March compared to the same time a year ago, according to the DAT North American Index.

Within the U.S. the year-over-year change was even more dramatic. A 64% increase was divided among the three equipment categories: vans were up 63%, flatbeds 58% higher and up 70% for refrigerated trailers.

Compared to February, freight volume increased 17% in March.

Extraordinary volume from December through February was attributable to extreme winter weather that disrupted supply chains nationwide during what is usually a slow season, said DAT. In March, however, freight volume also received a boost from increased economic activity and normal seasonal trends, in addition to pent-up demand from recurring storms.

Much of the increased seasonal volume was in the flatbed segment, where load availability rose 38% compared to February, while van freight added 10% and reefer loads increased 7%.

The continued pressure on spot market capacity buoyed spot market rates to new heights in March, as well. Year-over-year rate increases were significant for all three major equipment types: 25% for vans, 20% for reefers and 13% for flatbeds.

Compared to February 2014, when extreme weather led to a shift of unusual freight volumes to the spot market, rates in March rose 6.7% for vans, 3.6% for reefers, and 4.8% for flatbeds.

Rates are cited for line haul only, excluding fuel surcharges, which increased on a month-over-month basis but declined compared to March 2013.

The DAT North American Freight Index reflects spot market freight availability on the DAT Network of load boards in the United States and Canada.