Truckload linehaul rates rose 5.7% in April compared to the same time in 2013 and are up 4.6% since February, according to new readings from the Cass Truckload Linehaul Index, hitting a record high for the second consecutive month.

Demand continues to improve while capacity tightens, due to the increase in demand as well as freight carriers exiting the industry, said Cass. The investment firm, Avondale Partners, which provides analysis of the index, continues to predict increases of 4% to 6% in contracted linehaul rates in 2014.

Meantime, all-in intermodal costs, which include linehaul, fuel and accessorial charges, reached a new high in the Cass Intermodal Price Index, gaining 1.4% from the same time a year ago in April and 1% from March.

According to Cass, intermodal rates are expected to remain relatively flat in the near term, but rising intermodal volumes, combined with increasing truckload rates, should ultimately lead to further increases in intermodal costs.

The Cass Truckload Linehaul Index tracks market fluctuations in per-mile truckload pricing. It isolates the linehaul component of full truckload costs from other components, such as fuel and accessorials. The Cass Intermodal Price Index tracks changes in per-mile U.S. domestic intermodal costs. The index includes all costs associated with the move.

Both are derived from actual freight invoices paid on behalf of Cass’ clients, which totaled over $23 billion in 2013.