On Wednesday, July 23, 2008, Knight Transportation, Inc. (NYSE: KNX) expects to release second quarter earnings after the close of the market. Knight will be holding a live conference call with certain financial analysts to discuss the earnings release, the results of operations and other matters on Thursday, July 24, 2008, at 4:00 p.m. EDT. (Please note that since the call will begin promptly as scheduled, you will need to join a few minutes prior to that time).

The public will be able to listen and participate in the conference telephonically by dialing (866) 259-7123. An audio replay of the conference will be posted on the Company’s website for at least seven (7) days after the meeting (www.knighttrans.com/shareholders/audio).

The Company assumes no responsibility to update any information posted on its web site.

The conference may contain forward-looking statements made by the Company that involve risks, assumptions and uncertainties that are difficult to predict. Investors are directed to the information contained in Item 7A (“Quantitative and Qualitative Disclosures About Market Risk”) of Part II of the Company’s Annual Report on Form 10-K, filed with the U.S. Securities and Exchange Commission, for a discussion of the risks that may affect the Company’s future operating results. Actual results may differ.

Knight Transportation, Inc., Phoenix
David Jackson, 602-269-2000