CDL general knowledge practice test

B: 10,000 pounds. Class A covers combinations over 26,000 pounds GCWR where the towed unit's GVWR (or actual or registered weight) is over 10,000 pounds. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: Section 1: Introduction, page 26.

D: Safety for yourself and other road users. Safety for yourself and others on the road is the most important reason to inspect your vehicle. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: 2.1.1 Why inspect?, page 32.

A: Stop immediately. Low, dropping or fluctuating oil pressure means stop immediately; without oil the engine can be destroyed rapidly. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: 2.1.5 Seven-step inspection method, page 37.

B: Whenever the road is wet, icy or snow covered. With poor traction the retarder can make the drive wheels skid, so turn it off whenever the road is wet, icy or snow covered. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: 2.3.4 Retarders, page 46.

D: Perception distance, reaction distance and braking distance. Total stopping distance is perception distance plus reaction distance plus braking distance. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: 2.6.1 Stopping distance, page 51.

C: The vehicle in front of them. The vehicle trucks and buses most often hit is the one in front of them, and the most frequent cause is following too closely. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: 2.7.1 Space ahead, page 54.

B: Another driver may turn into you, and you may be trapped when you need to change lanes. Another driver may change lanes suddenly into you, and you may be trapped when you need to change lanes. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: 2.7.3 Space to the sides, page 56.

D: Turn wide as you complete the turn, keeping the rear of the vehicle close to the curb. Turn wide as you complete the turn and keep the rear close to the curb so others can't pass on the right. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: 2.7.6 Space for turns, page 57.

A: Slow down and change lanes away from the incident when safe. Move-over laws tell you to slow down and move out of the lane next to stopped emergency or roadside vehicles. If you can't safely change lanes, slow down and pass carefully. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: 2.8.1 Importance of seeing hazards, page 62.

D: A passive crossing. A passive crossing has no traffic control device, so the decision to stop or go rests entirely with you. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: 2.15.1 Types of crossings, page 79.

A: About one-third of an ounce. The liver can process only about one-third of an ounce of alcohol per hour, which is less than the alcohol in a standard drink. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: 2.22.1 Alcohol and driving, page 94.

B: Class B. A heavy straight vehicle with a GVWR, actual or registered weight over 26,000 pounds is a Class B vehicle. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: Section 1: Introduction, page 26.

C: The vehicle is put "out of service" until it is fixed. Inspectors who judge a vehicle unsafe will put it "out of service" until it is fixed. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: 2.1.1 Why inspect?, page 32.

B: 10 minutes. You must put out emergency warning devices within ten minutes of stopping on a road or shoulder. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: 2.5.2 Communicating your presence, page 49.

B: Bridges freeze before the road does. When the temperature drops, bridges freeze before the road; be especially careful near 32°F. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: 2.6.2 Matching speed to the road surface, page 52.

C: 1¾ seconds. The average perception time for an alert driver is 1¾ seconds, about 142 feet at 55 mph. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: 2.6.1 Stopping distance, page 51.

B: One second for each 10 feet of vehicle length. The rule is one second per 10 feet of vehicle length under 40 mph, and one extra second above 40 mph. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: 2.7.1 Space ahead, page 54.

C: A following driver may think you are turning left and try to pass you on the right. If you swing left first, a driver behind may think you are turning left, try to pass on the right, and get hit as you complete the turn. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: 2.7.6 Space for turns, page 57.

B: Passengers may cross in front of or behind it and often can't see you. Passengers may cross in front of or behind a stopped bus, and they often can't see you. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: 2.8.3 Drivers who are hazards, page 63.

C: Slow down, look and listen for a train, and be ready to stop at the tracks. The round yellow sign with black markings warns of a crossing ahead: slow down, look and listen for a train, and be ready to stop. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: 2.15.2 Warning signs and devices, page 79.

D: Only time. The liver works at a fixed rate, so only time, not coffee or a cold shower, will sober you up. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: 2.22.1 Alcohol and driving, page 94.

A: A Class C CDL. Class C covers vehicles of 26,000 pounds or less that are designed or used to carry 16 or more passengers including the driver, or that carry hazardous materials as defined in 49 CFR 383.5. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: Section 1: Introduction, page 26.

B: 4/32 inch. Front tires need at least 4/32-inch tread depth in every major groove. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: 2.1.3 What to look for, page 33.

A: One within 10 feet of the front or rear corner, and one 100 feet behind and one 100 feet ahead of the vehicle. On a two-lane or undivided road, place one device within 10 feet of the front or rear corner and one each about 100 feet behind and ahead of the vehicle. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: 2.5.2 Communicating your presence, page 49.

B: Wet ice from slight melting. Ice that has started to melt has a film of water on it, which makes it much more slippery than dry ice. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: 2.6.2 Matching speed to the road surface, page 52.