Truckload carrier Knight Transportation has revised upward expectations for its first quarter earnings.

Based on preliminary results, the company expects earnings per diluted share will range from 22 cents to 23, compared with its prior estimates of 19 cents to 21 cents, and 19 cents for the 2013 first quarter.

'There are several factors that contributed to our expectation of improved results for the first quarter of 2014,” said Chairman and CEO Kevin Knight.

“During the quarter we experienced greater demand for our capacity. This resulted in year over year improvement in revenue per tractor and growth in our brokerage business,” he said. “We have also seen strength in the used equipment marketplace, which is resulting in better than expected gain on sale of tractors and trailers.”

Knight said as the trucking environment remains strong the company will “continue to focus on improving production, growing its non-asset based businesses, recruiting and developing driving associates, providing industry-leading service, and intensifying our cost control efforts.''

Knight Transportation expects to release its 2014 first quarter earnings on April 23 shortly before market open.