Maine BMV CDL General Knowledge Practice Test 7
- Questions50
- Correct to pass40
- Passing score80%
- Minimum age16 years
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1. 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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2. 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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3. How does the working load limit of a tiedown relate to the force that would break it?
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Answer B: The working load limit is a fraction of the breaking strength and is the figure you use
The working load limit is set well below the point at which the device would fail, and securement is always calculated from the working load limit, never from breaking strength.
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4. What actually lowers the amount of alcohol in the bloodstream?
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Answer B: Time
The liver removes alcohol at a fixed rate, so nothing but the passage of time reduces blood alcohol concentration.
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5. How should a commercial driver treat the speed posted for a curve?
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Answer B: As a limit set for cars in good conditions, so a heavy or tall load calls for a lower speed
Posted curve speeds are based on passenger vehicles in good conditions, and a tall or heavy load can roll over well below that speed.
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6. At 55 mph, about how far does a vehicle travel during a typical 3/4 second perception time plus 3/4 second reaction time, before the brakes even begin to work?
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Answer C: About 120 feet
Each 3/4 second at 55 mph covers about 60 feet, so perception and reaction together use up roughly 120 feet before braking starts.
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7. What does the gross vehicle weight rating of a vehicle describe?
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Answer A: The maximum loaded weight of that single vehicle, as specified by the manufacturer
The rating is the manufacturer figure for the loaded weight of one vehicle, so it is a limit fixed in advance rather than a measurement of the load on board today.
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8. An article of cargo has been blocked so that it cannot move forward. How many tiedowns does the federal rule call for?
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Answer A: One tiedown for every 10 feet of article length, or any part of that
Blocking against forward movement lowers the requirement to one tiedown per 10 feet of length or fraction of 10 feet.
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9. Why should a driver avoid shifting gears in the middle of a turn at an intersection?
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Answer D: Shifting during the turn takes a hand off the wheel and can cost you control
Pick the gear before you begin turning; shifting in the turn removes a hand from the wheel and can interrupt power just when you need steady control.
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10. 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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11. A car that passed you on the right slows and stays alongside your trailer. What is the best response?
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Answer D: Ease off the accelerator so the car can move clear
A vehicle sitting beside a trailer is in a blind area and has nowhere to go if you need the lane, so the safest fix is to let it get ahead or behind.
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12. What frame defects are you looking for during the walkaround?
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Answer A: Cracks, bends or broken cross members
The frame carries the whole load, so cracked or bent rails and broken cross members are serious structural defects.
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13. What is checked about the clutch and the gearshift during the in-cab inspection?
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Answer D: That the clutch free play is within the range the manufacturer specifies
Too little or too much clutch free play causes slipping or dragging, either of which can leave the driver unable to select the gear a hill demands.
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14. Your truck has a backup alarm that sounds whenever reverse is selected. What may a driver rely on it for?
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Answer D: Very little; it warns some people but cannot show you what is behind the vehicle
An alarm may not be heard over yard noise or by someone wearing hearing protection, so it never replaces looking at the path yourself.
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15. A car is following you far too closely. What is the safest response?
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Answer A: Open up more space ahead so you can slow gradually, avoid sudden changes, and do not speed up
Extra room in front lets you slow smoothly instead of braking hard, which is exactly what the driver behind cannot cope with.
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16. What is the correct order for a double clutch downshift?
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Answer D: Release the accelerator and push the clutch to reach neutral, release the clutch and press the accelerator to raise engine speed, then push the clutch again and select the lower gear
A lower gear turns faster than the one being left, so engine speed has to be raised in neutral before that gear will engage cleanly.
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17. 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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18. A dock crew loads and straps the freight. Who is responsible for the load being legal and secure on the road?
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Answer D: The driver
Even when someone else loads and secures the freight, the driver must inspect it and remains responsible for it while driving.
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19. 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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20. 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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21. During the walkaround you notice one tire on an axle is a radial and the tire next to it is bias-ply. What should you do?
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Answer B: Treat it as a defect, because radial and bias-ply tires must not be mixed on the same axle
Radial and bias-ply tires flex and grip differently, so mixing them on one axle makes the vehicle handle unpredictably and is not allowed.
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22. You stop to check the load. Which set of things are you looking at?
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Answer C: Tight tiedowns, cargo that has not moved, secure doors and tarps still fastened
A cargo check covers the load and everything holding it: whether it has shifted, whether the devices are still tight, and whether doors and covers are still closed and fastened.
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23. Why does a heavy vehicle need a much larger gap than a car in order to cross or enter traffic?
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Answer C: Because it accelerates slowly and needs far more road and time to clear the intersection
Slow acceleration combined with the length of the vehicle means a gap that would feel comfortable in a car is nowhere near enough.
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24. How soon must warning devices be placed after a commercial vehicle stops on the traveled part or the shoulder of a highway?
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Answer D: As soon as possible and in any case within 10 minutes
The hazard warning flashers go on immediately and the warning devices must be in place as soon as possible, never later than 10 minutes after stopping.
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25. At highway speed, looking 12 to 15 seconds ahead means looking about how far down the road?
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Answer B: About a quarter of a mile
Twelve to fifteen seconds of travel is roughly a quarter of a mile at highway speed, while the same amount of time is about one block in slow city traffic.
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26. What must be true of the person who performs the annual periodic inspection?
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Answer D: They must meet the federal qualification requirements for an inspector
The inspection has to be done by someone who meets the federal training and experience requirements for inspectors, whoever employs them.
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27. Part of looking well ahead is planning an out. What does that mean?
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Answer B: Keeping an escape path in mind in case traffic stops suddenly
Because a heavy vehicle often cannot stop in time, good drivers continuously note where they could steer if the space ahead closes.
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28. Why does a load need to be balanced from side to side?
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Answer B: Because a heavy side raises the rollover risk and can overload the tires and springs on that side
An uneven load tips the balance of the vehicle in curves and pushes the tires and suspension on the loaded side past their rating.
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29. What does safe practice require of a commercial driver who wants to eat, drink or read a delivery note?
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Answer B: Handle it before or after driving, not while moving
Anything that takes hands, eyes or attention away from the task belongs outside the driving time, not inside it.
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30. 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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31. 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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32. You are hauling livestock and the trailer is only partly full. What should be done?
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Answer A: Use false bulkheads or partitions to keep the animals bunched together
Animals that can move around shift the center of gravity, so a partial load is bunched together with partitions to limit how far the weight can move.
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33. You are given a ratchet strap with a deep cut along one edge. What should you do?
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Answer C: Do not use it; a damaged tiedown cannot be relied on to hold its rated load
Cuts, burns, knots and broken stitching weaken a strap far below its marked working load limit, so it must be taken out of service.
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34. Most rollovers of loaded trucks on exit and entrance ramps happen for which reason?
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Answer B: The ramp was taken faster than the load could tolerate
A posted ramp speed is set for cars, and a loaded trailer with a high center of gravity can roll at a speed a car would take easily.
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35. What are you looking for when you check the hubs and wheel seals during the walkaround?
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Answer B: Leaking oil or grease, which can also contaminate the brake linings
A leaking hub seal starves the bearing of lubricant and the escaping oil or grease can soak the brake linings and cut braking power.
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36. While checking the in-cab gauges after start-up, what should the coolant temperature gauge do?
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Answer C: Rise gradually to the normal operating range
A healthy cooling system warms the engine slowly; a gauge that shoots up or stays cold points to a problem with the thermostat, coolant or sensor.
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37. How should speed and gears be handled when approaching a curve?
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Answer A: Slow to a safe speed and downshift before entering the curve
Braking and shifting are completed before the curve so the vehicle is settled and can pull gently through it without upsetting the load.
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38. A commercial vehicle stops on the shoulder of a one-way or divided highway. Where do the three warning devices go?
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Answer A: At 10 feet, 100 feet, and 200 feet back toward approaching traffic
Traffic arrives from one direction only, so all three devices are set back toward it at 10, 100, and 200 feet, and they must be out within ten minutes.
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39. What does the gross combination weight rating cover?
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Answer B: The maximum loaded weight of the power unit together with the trailer or trailers it tows
The combination rating takes in the power unit and everything behind it, loaded, as specified by the manufacturer.
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40. An unblocked crate 4 feet long and weighing 1,500 pounds needs at least how many tiedowns?
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Answer A: Two
A short article that weighs more than 1,100 pounds requires at least two tiedowns even though it is under 5 feet long.
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41. What is the correct way to test the parking brake before a trip?
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Answer C: With the parking brake set, put the vehicle in a low gear and gently try to move forward
A parking brake that holds against a gentle pull in low gear is working; if the vehicle moves, the brake needs adjustment or repair.
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42. A strap runs from an anchor point on one side of the trailer, over the load, and down to an anchor point on the opposite side. How much of its working load limit counts toward the total required?
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Answer C: All of it
A tiedown that is anchored on one side, passes over or around the cargo and is anchored on the other side counts its full working load limit toward the aggregate figure.
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43. Rust streaks are running outward from the lug nuts on one wheel. What does this most likely indicate?
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Answer C: The lug nuts may be loose
Rust trails spreading from the nuts are a classic sign that the nuts have worked loose and the wheel has been moving on the studs.
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44. What does the working load limit stamped on a chain or strap describe?
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Answer B: The maximum load the device is rated to hold in normal use
The working load limit is the rated safe capacity for everyday use, deliberately set well below the force that would break the device.
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45. For a modern truck with low-friction parts and a streamlined shape, which gear should be used going down a grade?
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Answer D: A gear lower than the one needed to climb the same grade
Newer trucks roll more freely than older ones, so the old rule of using the climbing gear no longer holds; a lower gear is needed for enough engine braking.
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46. What extinguisher rating is required on a vehicle carrying hazardous materials in amounts that need placards?
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Answer B: 10 B:C or more
Placarded loads carry a much higher fire risk, so the required extinguisher rating rises to at least 10 B:C.
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47. When should the horn of a commercial vehicle be used?
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Answer C: Only when it is needed to avoid a crash
An air horn is loud enough to startle other road users, so it is a warning device rather than a way to comment on other drivers.
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48. 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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49. 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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50. A roadside test shows a commercial driver has measurable alcohol in the system but below 0.04. What happens?
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Answer C: The driver is placed out of service for 24 hours
Any measurable alcohol while on duty results in an immediate 24 hour out of service order, even when the concentration is under the 0.04 limit.