Rates on the spot market keep heading higher, with all three major sectors posting increases, according to the freight matching service provider DAT.

Flatbed rates soared 7% March 23 through March 29 compared to the previous seven days, averaging $2.30 per mile, due to high demand, along with tight capacity and improving weather conditions. Flatbed rates finished 9.5% higher than February and 9% over March 2013.

Reefers also posted a gain, 2.7% for the week, for $2.27 per mile, finishing March 8.1% higher than February and 15% over March 2013.

Van rates continue increasing but had the smallest hike, just 0.5%, for an average of $2.10 per mile, while the pace appears to be moderating. Rates finished March 5.5% higher than February and 18% higher over March 2013.

The increases came as the number of spot market loads available was unchanged from the previous seven days while capacity increased 6.2%.

Also, load-to-truck ratios fell by 11% for vans and 12% for reefers, but flatbeds gained 8.6%.

“This year has been different in many ways, and one of those atypical trends is playing out right now, Northern geographies are in the forefront, with the first surge of spring freight on the spot market,” writes DAT Analyst Mark Montague in his Freight Talk Blog.

He says from March 21 through March 27, compared to the previous seven days, Kentucky, Indiana, Michigan, and Ohio, displayed the biggest growth in freight, an 8.1% increase, while the next-highest growth consisted of Illinois, Missouri, Kansas, and Nebraska, with an increase of 7.5%.

“We can probably look to winter weather and pent-up demand as contributors to the strong results in those Northern states,” he said.

Tied for third place, two clusters of states exhibited a 7.0% increase; Maryland, Virginia, West Virginia, North Carolina, South Carolina, known as the Mid-Atlantic region; along with Arkansas, Louisiana, Oklahoma and Texas, known as the South Central region.

“The upward trend in the South Central region, however, is not directly related to weather, but more likely evidence of the increased influence of the energy sector on the U.S. economy,” said Montague. “Energy-related freight trends continue to originate in the South Central region, not only because of drilling in that area, but also because heavy equipment moves from Texas and surrounding states in the spring to shale oil and gas drilling sites elsewhere in the country. Production in those areas was suspended during the winter months, re-starting in spring.”