The General Knowledge test is the one exam every commercial driver must pass, no matter what you'll drive. Our practice test gives you 109 real-style questions with a plain-English explanation on every answer, so you understand the rules of safe commercial driving instead of just memorizing them.
Start the General Knowledge practice test →Expect questions on vehicle inspection, basic vehicle control and shifting, communicating with signals and lights, managing space and speed, seeing hazards, controlling and recovering from skids, night, fog, and winter driving, railroad crossings, distracted and drowsy driving, drinking and driving (the 0.04 CDL limit), accident procedures, and securing cargo.
Each question on CDL Prep Hub comes with a plain-English explanation, so you learn the "why" behind every answer. Aim for 80% or better — that's the passing mark in most states — then take the timed exam simulator to rehearse the real format. No account needed; your best scores save in your browser.
Start the General Knowledge practice test →Study material based on the official CDL manual. Not the official state exam — always review your state's CDL handbook before testing.