Old Dominion will raise its base rates by an average of 4.3 percent in May, the company said.
The increase won't be felt across the board, officials said, but will instead take into account a customer's length of haul.
In July, the carrier increased the base rate by an average of 4.9 percent. Rates also rose by 4.9 percent in August 2012.
Todd Polen, OD's vice president of pricing, said the increase is needed due to rising equipment, wage and insurance costs, and in order to add capacity and develop new technology.
"Our customers are asking for more capacity, and more value added products and services. In order to meet that demand and deliver on the promises we have made to our customers, we must continue to build our network and systems. OD’s philosophy is to take a fair and equitable approach that minimizes the impact to our customers’ budgets yet at the same time, supports the value proposition we promised to the market place and OD stake holders," he said in a statement. "We believe the increase is essential in order to continue to provide our customers with an industry leading value proposition."