A driver who has passed the knowledge and skill tests for a combination vehicle (Class A) may operate a heavy straight vehicle (Class B) or a small vehicle (Class C), provided that he or she possesses the required endorsement(s). This video will you help prepare for the CDL Combination Vehicle written test. Visit http://cdlcollege.com/CDL_Courses_Fee... for drivers who prefer to stay close to home, or someone needing a refresher course.