CDL general knowledge practice test 4

B: With a long bed of loose, soft material, sometimes combined with an upgrade. Escape ramps use a long bed of loose soft material, sometimes with an upgrade, to stop runaway vehicles safely. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: 2.16.4 Proper braking technique, page 83.

C: Low tire pressure or worn tread. Hydroplaning is more likely with low tire pressure or worn tread, because shallow grooves don't carry water away well. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: 2.6.2 Matching speed to the road surface, page 52.

D: About one third. A wet road can double your stopping distance, so slow down by about a third, for example from 55 mph to about 35 mph. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: 2.6.2 Matching speed to the road surface, page 52.

D: Do not shift gears while crossing the tracks. Do not shift gears while crossing railroad tracks. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: 2.15.5 Crossing the tracks, page 82.

A: Don't use them; the only cure for fatigue is rest. Never take drugs to mask fatigue; rest is the only thing that cures it. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: 2.22.2 Other drugs, page 95.

B: Interstate. If you operate in both intrastate and interstate commerce, you must choose interstate commerce. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: 1.2.1 Interstate or intrastate commerce, page 28.

C: One-fourth or more. If one-fourth or more of the leaves in any leaf spring are missing, the vehicle is put out of service, though any defect can be dangerous. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: 2.1.3 What to look for, page 34.

A: You can almost always turn to miss an obstacle more quickly than you can stop. When you don't have room to stop, you can almost always turn to miss an obstacle faster than you can stop, though top-heavy vehicles and multiple trailers can flip. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: 2.17.1 Steering to avoid a crash, page 84.

A: Coming out of tunnels. Strong winds make it hard to stay in your lane, and the problem can be especially bad coming out of tunnels. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: 2.7.3 Space to the sides, page 56.

C: By a half or more. On packed snow, reduce speed by a half or more; on ice, slow to a crawl and stop as soon as you safely can. 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: A lowboy or car carrier. Low-slung units such as lowboys, car carriers, moving vans and possum-belly livestock trailers can get stuck on raised crossings. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: 2.15.6 Special situations, page 82.

D: Make them much worse. Mixing alcohol with other drugs can greatly increase their effects, so it is safest never to combine drugs and driving. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: 2.22.2 Other drugs, page 95.

A: A current medical examiner's certificate. Non-excepted interstate drivers must provide a current medical examiner's certificate (the DOT medical card) to their State Driver Licensing Agency. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: 1.2.2 Inter/intrastate commerce: Status non-excepted or excepted?, page 29.

B: The suspension holds up the vehicle and its load and keeps the axles in place. The suspension supports the vehicle and its load and keeps the axles in place, so broken parts can be extremely dangerous. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: 2.1.3 What to look for, page 34.

D: Applying the brakes while you are turning. Do not brake while turning, because it's easy to lock the wheels and skid out of control. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: 2.17.1 Steering to avoid a crash, page 84.

C: A hazard: a possible danger that may become an emergency. A hazard is any road condition or road user that is a possible danger. If the car cuts in front of you, it becomes an emergency. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: 2.8.1 Importance of seeing hazards, page 61.

B: It can roll over even at the posted speed limit for the curve. Testing shows a truck with a high center of gravity can tip over even when it is going no faster than the posted curve speed. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: 2.6.3 Speed and curves, page 53.

D: They become "not-certified" and may lose the CDL. Failing to provide and keep the medical examiner's certificate up to date makes the driver "not-certified," and the driver may lose the CDL. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: 1.2 Medical documentation requirements, page 28.

A: Poison fumes can get into the cab or sleeper berth. A broken exhaust system can let poisonous fumes into the cab or sleeper berth. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: 2.1.3 What to look for, page 35.

C: Turning the wheel back the other way once you've passed what was in your path. Countersteering means turning the wheel back in the other direction once past the obstacle; emergency steering and countersteering are two parts of one action. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: 2.17.1 Steering to avoid a crash, page 84.

B: You have more time to act before they become emergencies. Seeing hazards before they become emergencies gives you time to check mirrors, signal and change lanes or slow down. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: 2.8.1 Importance of seeing hazards, page 61.

A: It is easier to lock the wheels and cause a skid. Braking in a curve makes it easier to lock the wheels and skid, so slow to a safe speed before entering the curve. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: 2.6.3 Speed and curves, page 53.

C: Driving a fire truck during an emergency. Fire truck or rescue vehicle drivers during emergencies are listed among the excepted activities that do not need a federal medical card. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: 1.2.2 Inter/intrastate commerce: Status non-excepted or excepted?, page 29.

D: Three reflective warning triangles. The parked-vehicle warning devices must be three reflective triangles, or at least six fusees, or three liquid-burning flares. Two triangles, four fusees or one flare and one triangle fall short. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: 2.1.3 What to look for, page 35.

B: To your right. A move to your right is best; if the other driver realizes the mistake, their natural response is to return to their own lane. Wisconsin Commercial Driver's Manual (BDS356), based on the AAMVA 2025 CDL Manual: 2.17.1 Steering to avoid a crash, page 84.