Upgrade Class B to A CDL. Diamond Trucking School, Inc. offers this course to those individuals that have a Class B or Class "C" Commercial Driver License to be able to apply for an entry level position within the Transportation job sector with the additional skills and education needed to obtain a job requiring a Class A Commercial Driver License. This course is composed of four different areas of education. The student will spend a minimum of 18 hours of "behind the wheel" street driving, a minimum of 16 hours training on backing maneuvers, a minimum of 16 hours of proficiency, and a minimum of 30 hours of observation. The total minimum time for this class is 80 hours between all learning areas.