Trucking company Knight Transportation has upwardly revised estimates of its financial performance, ahead of releasing full numbers later this month.

Based on preliminary results, Knight now expects earnings per diluted share will range from 24 cents to 25 cents for the fourth quarter ending Dec. 31, compared with its prior estimates of 20 cents to 23 cents.

For the current quarter ending March 31, it expects earnings per diluted share will range between 19 cents and 21 cents, compared to prior estimates of 18 cents to 20 cents.

“Our improvement in results for the fourth quarter of 2013 was a result of better than expected performance in several key areas of our business,” Knight said in a statement. “We experienced improvement in our revenue per tractor, growth in our non-asset based businesses, and more effective cost management.”

The company believes this is a result of “improved freight demand and meaningful progress on several internal initiatives focused on improving production, recruiting and developing driving associates, providing industry-leading service, and intensifying our cost control efforts.”

Knight is expected to release its full fourth-quarter earnings on Jan. 29, shortly before the market opens.