CCDL Permit Prep

General Knowledge · page 13 of 19

General Knowledge questions 241–260

Part of the 376-question General Knowledge pool. Each answer cites the FMCSA CDL Manual or the federal rule it comes from.

Practise these as a timed set

  1. Does ABS always shorten a commercial vehicle's stopping distance?

    • ANo; it may or may not shorten the stop, but it helps prevent wheel lockup and preserve controlCorrect
    • BYes; it always cuts stopping distance in half
    • CYes; it guarantees an immediate stop on ice
    • DNo; ABS disables steering during hard braking

    ABS may or may not shorten stopping distance. Its core benefit is helping prevent wheel lockup so the driver can maintain steering control during hard braking.

    49 CFR § 393.55 · General Knowledge — ABS · verified 2026-06-30

  2. When driving at night, you should reduce speed so that you can stop within:

    • AA fixed 200 feet, whatever your headlights reach
    • BThe distance you can see ahead with your headlightsCorrect
    • CThe distance to the taillights of the vehicle ahead
    • DA fixed 500 feet, the high-beam dimming distance

    You should never overdrive your headlights. At night, adjust speed so you can stop within the distance your headlights illuminate — your visibility distance. This ensures you can stop before reaching any hazard you can see.

    FMCSA CDL Testing System — General Knowledge · General Knowledge — Night Driving · verified 2026-09-29

  3. You find damaged locking parts during a fifth-wheel inspection. What should you do before driving?

    • AIgnore the damage if the paint is intact
    • BTry a faster tug to force the lock closed
    • CHave the defective coupling corrected and verify it before useCorrect
    • DUse the air hoses to help hold the trailer

    Damaged coupling parts can allow separation. Do not drive with an improper coupling. More force or connected hoses cannot repair a damaged locking mechanism.

    Oregon DMV Commercial Driver Manual · 6.5.1 Combination walk-around inspection; 6.5.2 brake checks · verified 2026-09-07

  4. Under federal rules, what is the consequence of a first conviction for operating a CMV with a blood alcohol concentration (BAC) of 0.04% or higher?

    • AA federal fine of $500 with no effect on the CDL
    • BA 30-day out-of-service order, then reinstatement
    • CDisqualification of the CDL for at least one yearCorrect
    • DLifetime disqualification, even for a first offense

    Under 49 CFR 383.51 a first DUI conviction in a CMV (BAC 0.04% or higher) disqualifies the driver for at least one year, or three years if the vehicle was carrying placarded hazardous materials. A second conviction is a lifetime disqualification. Federal rules set the disqualification; any fine is set by state law.

    49 CFR § 383.51 · General Knowledge — Alcohol and Drug Rules · verified 2026-09-08

  5. Under the FMCSA's 'Texting while driving' regulation, commercial drivers are prohibited from:

    • AManually entering or reading text on a hand-held device while drivingCorrect
    • BTexting after parking safely off the roadway
    • CUsing hands-free voice-to-text technology while the vehicle is in motion
    • DUsing a built-in factory navigation system while the vehicle is moving

    FMCSA's texting ban prohibits a CMV driver from manually entering or reading text while driving, including while temporarily stopped at a traffic light or sign. It does not apply after the vehicle is safely parked off the roadway.

    49 CFR § 392.80 · General Knowledge — Distracted Driving · verified 2026-06-30

  6. What does a flashing red traffic signal require you to do?

    • AFlash your hazard lights and proceed
    • BSlow down and proceed with caution
    • CYield to pedestrians only, not to cross traffic
    • DStop completely, then proceed when safeCorrect

    A flashing red signal has the same meaning as a STOP sign: you must come to a complete stop, yield to all cross-traffic and pedestrians, then proceed when it is safe.

    FMCSA CDL Testing System — General Knowledge · General Knowledge — Traffic Control Signals · verified 2026-06-30

  7. A driver convicted of a second serious traffic violation involving a CMV within 3 years will face:

    • AA fine of $2,500 and a warning
    • BMandatory CDL disqualification for at least 60 daysCorrect
    • CMandatory CDL disqualification for 1 year
    • DPermanent CDL revocation

    Under 49 CFR 383.51, two serious traffic violations involving a CMV within 3 years result in at least a 60-day CDL disqualification. Three such violations within 3 years result in at least 120 days.

    49 CFR § 383.51 · General Knowledge — Serious Traffic Violations · verified 2026-06-30

  8. For a property-carrying driver subject to federal HOS, what is the 8-day on-duty limit when the carrier operates every day?

    • A60 hours
    • B84 hours
    • C80 hours
    • D70 hoursCorrect

    Under 49 CFR 395.3(b)(2), a property-carrying driver may not drive after accumulating 70 hours on duty in any 8 consecutive days when the carrier operates every day.

    49 CFR § 395.3(b)(2) · General Knowledge — Hours of Service Overview · verified 2026-06-30

  9. For a property-carrying carrier that does not operate every day, after how many on-duty hours in any 7 consecutive days may a driver no longer drive?

    • A60 hoursCorrect
    • B50 hours
    • C65 hours
    • D70 hours

    Under 49 CFR 395.3(b)(1), a property-carrying driver for a carrier that does not operate every day may not drive after accumulating 60 on-duty hours in any 7 consecutive days.

    49 CFR § 395.3(b)(1) · General Knowledge — 60-Hour Rule · verified 2026-06-30

  10. When planning a HazMat trip that crosses state lines, what should the carrier or driver verify?

    • AObtain a new bill of lading for the destination state
    • BChange the placard colors to match that state's own requirements
    • CReport to the nearest weigh station to obtain clearance first
    • DVerify the applicable state, tribal, and federal routing rules for the cargo and routeCorrect

    HazMat routing designations can be made by a state or Indian tribe, and federal routing rules also apply. Verify the rules that cover the cargo and planned route; this is route planning, not a universal weigh-station clearance requirement.

    49 CFR § 397.67 · 49 CFR 397.67: Motor carrier responsibility for hazardous-material routing · verified 2026-09-08

  11. What is the purpose of the 'service air line' (blue air line) in a tractor-trailer combination?

    • ATo operate the trailer parking brakes only
    • BTo supply air for the trailer's air suspension system
    • CTo control the trailer's service (foot) brakes during normal driving and brakingCorrect
    • DTo inflate the trailer tires during a blowout

    The service air line (blue or black, often blue) connects the tractor's service brake air supply to the trailer's service brake system, allowing the driver's foot brake to control all axles in the combination.

    FMCSA CDL Testing System — General Knowledge · General Knowledge — Air Lines · verified 2026-06-30

  12. What is the purpose of the 'emergency air line' (red air line) in a tractor-trailer?

    • ATo maintain air pressure in the tractor's air tanks
    • BTo supply air for the service brakes only
    • CTo supply the air that keeps the trailer spring brakes releasedCorrect
    • DTo operate the trailer's air horn

    The emergency air line (red) supplies air pressure to the trailer's spring brake relay valve, which keeps the trailer spring brakes released during normal operation. If it disconnects or loses pressure, the spring brakes automatically apply.

    FMCSA CDL Testing System — General Knowledge · General Knowledge — Air Lines · verified 2026-06-30

  13. What is 'engine braking' and when should it be used?

    • AOnly used when the service brakes have completely failed
    • BDownshifting to use the engine's compression to help slow the vehicle; most effective on long downgradesCorrect
    • COnly allowed when driving in snowy or icy conditions, and never on dry pavement
    • DKeeping the engine at idle speed to reduce fuel consumption

    Engine braking (compression braking) uses downshifting and the engine's resistance to help slow the vehicle. It is most effective on long downgrades to preserve service brake effectiveness. It should be turned off on slippery roads.

    FMCSA CDL Testing System — General Knowledge · General Knowledge — Engine Braking · verified 2026-06-30

  14. What is an electronic logging device (ELD)?

    • AA device that automatically records a driver's driving time and helps accurately record hours of serviceCorrect
    • BA GPS unit used only for navigation
    • CA paper logbook
    • DA device that records only fuel purchases

    49 CFR 395.2 defines an ELD as a device or technology that automatically records a driver's driving time and facilitates accurate recording of hours of service.

    49 CFR 395.2 Definitions · 395.2 (Electronic logging device) · verified 2026-09-25

  15. If a passenger carrier operates every day of the week, after being on duty for more than how many hours in any 8 consecutive days may the driver not drive?

    • A70 hoursCorrect
    • B60 hours
    • C80 hours
    • DThe 70/8 rule only applies to property drivers

    Under 49 CFR § 395.5(b)(2), when the passenger carrier operates every day of the week, the driver may not drive after being on duty for 70 hours in any 8 consecutive days. A carrier that does not operate every day uses the separate 60-hour/7-day limit.

    49 CFR § 395.5(b)(2) · Hours of Service — Passenger Carrier 70-Hour · verified 2026-09-08

  16. After a HOS violation is discovered at a weigh station, what can happen to the driver?

    • ANothing — violations are only tracked annually
    • BThe driver may continue driving if they sign a waiver
    • COnly the carrier is fined
    • DThe driver may be placed out of service at the roadsideCorrect

    An HOS violation can result in the driver being placed out of service at the roadside until enough off-duty time has accumulated to comply with the hours-of-service regulations.

    49 CFR § 395.13 · Hours of Service — Enforcement · verified 2026-09-08

  17. How many previous consecutive days must a driver carry a copy of each record of duty status (RODS or ELD record) while on duty?

    • A7 daysCorrect
    • B30 days
    • C6 months
    • D1 year

    Under 49 CFR § 395.8(k)(2), a driver must carry a copy of each record of duty status for the previous 7 consecutive days while on duty and make it available for inspection. The motor carrier has a separate duty to retain records for at least 6 months.

    49 CFR § 395.8(k) · Hours of Service — Record Retention · verified 2026-09-08

  18. When your vehicle catches fire while you are moving, what is the FIRST thing to do?

    • AOpen the windows to determine the fire's location
    • BPull safely off the road and stop far from trafficCorrect
    • CIncrease speed to reach the nearest fire station
    • DApply the brakes hard to stop quickly in the travel lane

    The first action for a vehicle fire while moving is to safely leave the road — pull as far off the road as possible, away from other vehicles and structures. Only then assess and fight the fire if safe to do so.

    FMCSA CDL Testing System — Emergency Maneuvers · Emergency Maneuvers — Vehicle Fire · verified 2026-09-08

  19. If your brakes begin to fade on a long downgrade, what is the BEST thing to do next time you descend that grade?

    • AUse the parking brake to supplement service brakes
    • BWait until the brakes fade before using the engine
    • CUse a lower gear from the top of the gradeCorrect
    • DDrive faster to reduce the time spent on the grade

    To prevent brake fade on downgrades: select a lower gear before beginning the descent and use engine braking throughout to keep speed under control, minimizing service brake use and heat buildup.

    FMCSA CDL Testing System — Emergency Maneuvers · Emergency Maneuvers — Downgrade Braking · verified 2026-09-08

  20. Before driving a commercial motor vehicle, what must the driver be satisfied about?

    • AThe required parts and accessories are in good working orderCorrect
    • BA walk-around alone was completed, even if a defect was found
    • COnly the tires and service brakes have been checked
    • DThe vehicle passed an annual inspection within the last 12 months

    Before driving, 49 CFR 392.7 requires the driver to be satisfied that the listed parts and accessories are in good working order. A consistent pre-trip inspection, such as Oregon's seven-step method with a walk-around, helps make that safety decision; do not operate an unsafe vehicle.

    49 CFR § 392.7 · 392.7(a) Equipment, inspection and use · verified 2026-09-07