If you need to practice commercial driving before you take your skills test, you must first obtain a commercial learner’s permit (CLP) and hold it for at least 14 days. Your CLP will allow you to practice operating commercial motor vehicles (CMVs) while supervised by a person with a Commercial Driver’s License (CDL). The requirements for a CLP include passing a set of official knowledge tests for the class and the type of vehicles you plan to drive. However, regardless of the vehicles, all applicants for a CLP must pass the General Knowledge test, which covers general commercial driving theory.
The official General Knowledge test covers many topics, including pre-trip inspections. Federal regulation 49 CFR § 392.7 lists the most critical items to inspect. You must be sure that all these systems are in good working order before you drive the vehicle: brakes, coupling devices (if so equipped), emergency equipment, horn, lights and reflectors, mirrors, steering, tires, wheels and rims, and windshield wipers.
All questions on the General Knowledge test are based on the official Washington CDL manual (Washington CDL Handbook 2026). To prepare for this test, you should start by studying this CDL manual. But don’t be satisfied with that alone. There’s a large amount of complex information to absorb and memorize. And we can help.