CDLCareerNow.com and TheTruckersReport.com have online practice tests and answers at no charge, as of April 2015. DMV.org also offers online practice tests with answers; however, this website charges a fee to access those tests.
One of the first steps in becoming a truck driver is to obtain a CDL instruction permit, which involves passing the General Knowledge test and any other knowledge test for the specific truck type the learner wishes to drive. For example, if the potential truck driver wishes to drive tankers, he would have to pass the General Knowledge test and the Tank Vehicle test. CDLCareerNow.com has practice tests for six CDL tests: General Knowledge, Passenger, Tank Vehicle, Hazardous Materials, Combination of Hazardous Materials and Tank Vehicle, and School Bus.
In addition, the driver must take a skills test in the classification of truck that he wishes to drive. There are three truck classifications, A, B and C, based on the truck’s gross vehicle weight rating and the average cargo weight. A state may also issue a CDL license with an air brake restriction if the driver fails the air brake component of the General Knowledge test or performs the skill test in a truck without air brakes.
If the driver wants a passenger endorsement, he must take the skills test in a passenger vehicle. The school bus endorsement has a similar requirement.