New York DMV CDL General Knowledge Practice Test 3
Test 3 of 5. Pick an answer for each question to see if it is right and why; your score appears at the end. You need 40 correct answers to pass, the same ratio as the real New York test.
- Questions50
- Correct to pass40
- Passing score80%
- Minimum age18 years
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1. You are entering a freeway from a short ramp with a fully loaded trailer. What should you do?
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Answer A: Begin building speed early and wait for a large gap
A loaded vehicle accelerates slowly, so it needs both a running start and a much larger gap than a car would use.
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2. What happens to braking performance if oil or grease reaches a brake lining?
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Answer B: That brake loses much of its effect and the vehicle can pull to one side
A contaminated lining cannot grip the drum, so that wheel contributes little braking and the vehicle pulls toward the side that is still working.
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3. Your axle weights are legal, but the tires on that axle are rated below the weight it is carrying. What controls?
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Answer B: The lower figure, so the tires may not be loaded beyond their marked rating
You may never exceed the rating marked on a tire, even when the axle limit would allow more, because an overloaded tire builds heat and can fail.
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4. A straight truck has a long body behind the rear axle. What happens to that overhang in a sharp left turn?
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Answer D: It swings out to the right and can strike a vehicle or an object on that side
Body that hangs behind the rear axle swings the opposite way to the turn, so the tail of the truck sweeps out into the next lane or over the curb.
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5. You miss a gear while double clutching and the transmission is stuck in neutral. What should you do?
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Answer B: Return to neutral, release the clutch, bring engine speed to match road speed and try again
Forcing the lever damages the gears; matching the engine speed to the road speed lets the gear engage cleanly on the next try.
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6. Which items belong to the trailer part of the walkaround inspection?
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Answer D: Landing gear, doors, tires, wheels, lights, reflectors, frame and cargo securement
The trailer has its own running gear, lighting, structure and load, and all of it is the responsibility of the driver pulling it.
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7. Federal rules require a power unit that is not carrying placarded hazardous materials to have a fire extinguisher with which minimum rating?
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Answer A: One rated 5 B:C or more, or two rated 4 B:C or more each
The minimum is a single unit rated 5 B:C or more, or two units of at least 4 B:C each, which is enough to attack a fuel or electrical fire.
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8. Below 40 mph, what following distance does the standard commercial rule of thumb call for?
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Answer C: One second for every 10 feet of vehicle length
The base rule allows one second of space for each 10 feet of vehicle length while speed stays under 40 mph.
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9. What are the rules for using your turn signal before a turn or lane change?
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Answer A: Signal early, keep the signal on until the turn is finished, then cancel it
An early, continuous signal tells others what you plan to do; cancelling afterward keeps the signal from misleading them.
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10. In a vehicle with a manual transmission, when should the clutch be pushed in during a normal stop?
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Answer A: Just before the engine would stall, when the vehicle is nearly stopped
Staying in gear until the last moment keeps engine braking and steady control, so the clutch goes down only when the engine is about to drop below idle.
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11. How can a driver tell that a shipment includes hazardous materials?
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Answer B: The shipping paper describes them and the packages carry hazard warning labels
Hazardous materials are identified on the shipping paper with their shipping name and hazard class, and the packages themselves carry labels showing the hazard.
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12. How does a typical escape ramp stop a runaway vehicle?
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Answer B: With a bed of loose gravel or sand, often on an upgrade
Escape ramps use deep loose material, usually combined with a rising grade, so the vehicle is slowed gradually instead of being stopped by impact.
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13. Which set of emergency equipment must be carried on a commercial motor vehicle?
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Answer D: A fire extinguisher, spare electrical fuses unless the vehicle has circuit breakers, and warning devices
The required kit is a properly charged and rated fire extinguisher, spare fuses when the vehicle uses them, and warning devices for a stopped vehicle.
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14. Where should a driver expect fog to form first?
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Answer D: In low ground, near water and in valleys
Cool moist air settles in low places, so fog patches appear in hollows, river valleys and near lakes before they appear anywhere else.
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15. What is the best practice when fog is thick enough to hide the road ahead?
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Answer B: Slow down before entering the fog, and if visibility is too poor, pull off into a rest area or truck stop until it improves
The safest choice in heavy fog is not to be driving in it, and if you are already in it your speed has to come down before your visibility does.
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16. Which combination of warning devices meets the requirement for a stopped commercial vehicle?
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Answer A: Three reflective triangles, or six fusees, or three liquid burning flares
A vehicle may carry three bidirectional reflective triangles, six fusees or three liquid burning flares as its warning devices.
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17. Which clues warn you that a parked car may pull out or open a door?
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Answer A: Exhaust smoke, turned front wheels, a person in the seat
Signs of life in a parked vehicle, such as a running engine, turned wheels or an occupant, mean it may move or open a door into your path.
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18. At the scale your tractor drive axles are overweight while the trailer axles have room. Sliding the trailer tandems forward will do what?
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Answer C: Move weight off the drive axles and onto the trailer axles
Sliding the trailer tandems forward brings the rear support closer to the load, so the trailer axles pick up more weight and the drive axles carry less; sliding them rearward does the opposite.
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19. You are about to cross a long, high bridge with a light load in gusty wind. What should you do?
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Answer C: Slow down and be ready for a sudden push
Wind is strongest where a bridge leaves the shelter of the land, and lower speed gives you time to correct when the first gust hits.
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20. When should a lower gear be selected for a long downgrade?
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Answer D: Before you start down the hill
The gear is chosen at the top, while speed is still low, because a heavy vehicle already rolling fast may not go into a lower gear at all.
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21. Which set of maneuvers makes up the basic control skills part of the commercial driving test?
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Answer D: Straight line backing, offset backing, parallel parking and alley docking
The basic control skills test is carried out off the road and consists of low speed exercises such as straight line backing, offset backing, parallel parking and the alley dock.
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22. Who may remove an out-of-service sticker from a commercial vehicle?
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Answer B: Only an authorized person, and only after the defect that caused it has been repaired
The sticker stays on the vehicle until the repairs are made and an authorized person removes it, so nobody can simply peel it off and drive away.
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23. Why must exhaust components be checked for contact with other parts of the vehicle?
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Answer B: Hot exhaust parts touching fuel lines, tires or wiring can start a fire
Exhaust pipes run hot enough to ignite fuel and melt insulation, so they must be kept clear of the fuel system, the tires and the electrical harness.
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24. Which exhaust system condition must be reported as a defect?
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Answer B: A section repaired by wrapping tape or patching material around the pipe
Exhaust parts may not be patched with wrap or tape, because the repair does not contain the gas or the heat and it fails quickly in service.
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25. Why should the radio, the fan and other noisy equipment be switched off during a required stop at a railroad crossing?
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Answer C: So that an approaching train can be heard
The rules require the driver to look and listen along the track, and on a double track crossing a passing train can hide a second one, so hearing matters as much as seeing.
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26. An unblocked crate 4 feet long and weighing 900 pounds needs at least how many tiedowns?
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Answer D: One
An article 5 feet or less in length and 1,100 pounds or less in weight is covered by a minimum of one tiedown.
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27. A commercial vehicle stops on the shoulder of an undivided two-lane road that carries traffic in both directions. Where do the warning devices go?
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Answer B: Within 10 feet of the vehicle, plus 100 feet to the front and 100 feet to the rear
On a two-way road the devices must mark the vehicle itself and warn traffic approaching from each direction, and they must be in place within ten minutes.
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28. You have backed into the same loading bay every week for a year. How often should you still get out and walk to the rear before backing?
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Answer D: Every time, since the area can change while you are away from it
A familiar space is no guarantee; vehicles, pallets, people and overhead obstructions appear between one visit and the next, so you check on every occasion.
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29. At what time of day do drowsy driving crashes occur most often?
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Answer A: Between midnight and 6 a.m.
The body clock makes people sleepiest in the early morning hours, which is when most fatigue-related crashes happen.
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30. How is free play in the steering wheel measured during the inspection?
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Answer B: By turning the wheel until the front wheels just start to move and noting the movement
Play is the movement at the rim that produces no movement at the road wheels, so it is measured by turning until the wheels first respond.
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31. How long does a commercial driver from another jurisdiction have to apply for a New York commercial license after moving?
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Answer A: 30 days after establishing residency
A commercial driver who becomes a New York resident must apply for a New York commercial license within 30 days.
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32. Why must tiedowns be rechecked during a trip even when they were tight at the start?
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Answer C: Road vibration and cargo movement can loosen them as the miles go by
Straps and chains settle and loosen as the vehicle bounces and the cargo shifts slightly, so the load must be rechecked at the required intervals.
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33. What is the most common cause of a front-wheel skid, where the vehicle keeps going straight even though you turn the wheel?
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Answer B: Driving too fast for the conditions
A front-wheel skid usually comes from too much speed for the traction available; the only cure is to let the vehicle slow down and stop turning or braking so hard.
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34. What restrictions apply to a New York commercial driver license holder who is under 21?
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Answer C: Driving only within New York, with no hazardous materials and no students on a school bus
New York issues Class A, B and C commercial licenses from age 18, but a holder under 21 may drive only in intrastate commerce and may not carry hazardous materials or transport students in a school bus.
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35. Cargo carried inside the cab must never do which of these?
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Answer C: Block the driver view, restrict arm or leg movement, or block an emergency exit
Anything inside the cab must leave the driver a clear view, free movement of the arms and legs, and an unobstructed way out of the vehicle.
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36. What does the commercial driver manual tell you to do with the parking brake when you leave your vehicle?
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Answer B: Apply the parking brake every time you leave the vehicle
The manual is explicit that the parking brake goes on whenever the driver leaves the vehicle, because once nobody is at the controls it is the only thing holding it.
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37. What should you check about the fuel tank during the walkaround?
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Answer A: That it is securely mounted, the cap is on tight and there are no leaks
A loose tank or a missing cap can spill fuel, and any fuel leak is a fire hazard that makes the vehicle unsafe to drive.
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38. What happens when too much of the load sits over the steering axle?
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Answer D: The vehicle becomes hard to steer and the axle and its tires can be damaged
Weight beyond the front axle rating makes the steering heavy and can overload the axle and the tires carrying it.
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39. An enforcement officer inspects your vehicle at the roadside and attaches an out-of-service sticker. What may you do?
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Answer C: Nothing until the defect is repaired; the vehicle may not be driven
An out-of-service order means the vehicle is unsafe, and no schedule, load or destination allows it to be driven before the defect is corrected.
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40. Federal rules keep recapped and retreaded tires off the front wheels of which vehicle?
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Answer B: Any bus carrying passengers
The federal rule names buses: a bus may not run with regrooved, recapped or retreaded tires on its front wheels, because a steer tire failure with passengers aboard takes away steering control.
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41. What civil penalty applies when a commercial driver refuses a chemical test in New York?
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Answer D: $550
New York sets a 550 dollar civil penalty for a commercial driver's chemical test refusal, along with a license revocation of at least 18 months.
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42. The combined working load limit of the tiedowns on a load must equal at least what share of the cargo weight?
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Answer C: One half of the cargo weight
Federal securement rules set the aggregate working load limit at no less than half the weight of the article or group of articles being held.
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43. What should be done before a night trip to get the most from your headlights?
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Answer C: Clean the windshield, the mirrors and the lights
Dirt on glass and lenses cuts both the light you throw down the road and the light that reaches your eyes, so cleaning is the cheapest night safety measure there is.
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44. Why do worn tires lose grip so quickly on a wet road?
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Answer D: Shallow tread cannot move water out from under the tire
The grooves in a tire exist to channel water away so the rubber can touch the road, and a worn tire has lost that capacity.
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45. You drop your phone on the floor of the cab while driving. What do federal rules require?
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Answer A: Leave it, because reaching for it while driving is banned
Federal rules forbid reaching for a mobile device in any way that takes the driver out of a seated, belted driving position.
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46. You are moving an oversized load under a permit that requires a pilot vehicle. What is the pilot vehicle there to do?
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Answer B: Warn other traffic and check the route ahead for clearances and hazards
Escort or pilot vehicles warn approaching traffic and scout the route for low bridges, narrow spots and other hazards that a wide or long load cannot pass.
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47. The scale shows that your combination is over the legal gross weight. Why will sliding the tandems not fix it?
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Answer B: Because sliding the axles changes where the weight sits, not how much there is
Repositioning axles redistributes weight between axle groups; when the total is too high, freight has to come off the vehicle.
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48. A 40 foot straight truck and a 70 foot tractor-trailer make the same right turn. Which needs more room and why?
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Answer B: The tractor-trailer, because the longer the vehicle the farther inside the rear wheels track
Off-tracking grows with the distance between the front and rear axles, so the longer combination cuts the corner much more sharply and needs extra room.
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49. Why does extra weight make a long downgrade more dangerous even when the brakes are in good order?
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Answer B: Gravity adds to the momentum and the brakes heat up faster
The heavier the vehicle, the more energy the brakes must turn into heat, and heat is exactly what makes brakes fade on a long descent.
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50. How do you avoid the sharp lurch that comes at the very end of a stop in a heavy vehicle?
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Answer A: Ease off the brake pressure just before the vehicle actually comes to rest
A smooth stop is finished by reducing pedal pressure as the vehicle settles, so the suspension does not rock the cab and the load forward.