EXHIBIT 21 SUBSIDIARIES OF WERNER ENTERPRISES, INC. SUBSIDIARY STATE OF INCORPORATION 1. Werner Leasing, Inc. Nebraska 2. Werner Aire, Inc. Nebraska 3. Gra-Gar, Inc. Nebraska 4. Drivers Management, Inc. Nebraska 5. Frontier Clinic, Inc. Nebraska 6. Fleet Truck Sales, Inc. Nebraska 7. Professional Truck Drivers School, Inc. Nebraska 8. Werner Transportation, Inc. Nebraska 44