CCDL Permit Prep

General Knowledge · page 12 of 19

General Knowledge questions 221–240

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. Cargo that is not properly secured in a trailer can affect vehicle handling by:

    • AShifting during transport, changing the vehicle's weight distribution and potentially causing loss of controlCorrect
    • BReducing the overall weight of the vehicle
    • CIncreasing fuel efficiency due to reduced rolling resistance
    • DReducing wear on the trailer axle, an unlikely side effect not caused by unsecured cargo

    Improperly secured cargo can shift during acceleration, braking, or cornering, dramatically altering axle weight distribution. This can cause understeer, oversteer, or rollover.

    49 CFR § 393.100 · Weight — Cargo Securement · verified 2026-06-30

  2. Under the federal Interstate Highway System limits, what maximum weight generally applies to a tandem axle group?

    • A20,000 lbs
    • B40,000 lbs
    • C34,000 lbsCorrect
    • D44,000 lbs

    Federal Interstate Highway System limits generally set a 34,000-pound tandem-axle limit. State rules, permits, axle spacing, and other exceptions can change what applies on a specific route.

    23 U.S.C. § 127 · Weight — Tandem Axle Limits · verified 2026-06-30

  3. A box truck is outside the vehicle categories in § 392.10. What is the federal minimum approach duty at a rail grade crossing?

    • AStop at every crossing regardless of conditions under this section
    • BStop only at signs bearing the word Bus
    • CProceed at exactly 15 mph
    • DApproach slowly enough to stop before the rail and cross only after checking that the course is clearCorrect

    Section 392.11 requires a stoppable speed and a clear-course check. Signals are not the only possible reason to stop, and the rule does not specify a universal 15-mph speed.

    49 CFR § 392.11 · 392.11 slowing and clear-course requirement · verified 2026-09-07

  4. What does a CDL Medical Examiner's Certificate (MEC) prove?

    • AThat the driver meets the physical qualifications to operate a CMVCorrect
    • BThat the driver has passed the CDL knowledge and skills tests
    • CThat the vehicle passes the annual DOT inspection
    • DThat the driver is authorized to haul hazardous materials

    The Medical Examiner's Certificate (Form MCSA-5876) confirms that the driver has been examined by a certified medical examiner and meets the physical qualification standards in 49 CFR Part 391.

    49 CFR § 391.45 · General Knowledge — Physical Qualifications · verified 2026-06-30

  5. Which of the following results in permanent (lifetime) CDL disqualification upon a FIRST conviction?

    • AA single speeding ticket 15 mph over the limit
    • BFailing to yield at a stop sign twice
    • CA third lane-change violation within a 12-month period
    • DUsing a CMV in the commission of a felony involving controlled substancesCorrect

    Using a CMV to commit a felony involving manufacturing, distributing, or dispensing controlled substances results in lifetime CDL disqualification on the first offense.

    49 CFR § 383.51 · General Knowledge — Disqualifying Offenses · verified 2026-06-30

  6. What acuity does the general vision standard in 49 CFR 391.41 require?

    • AAt least 20/40 in each eye, with or without correctionCorrect
    • BPerfect color vision (no color blindness), regardless of visual acuity
    • C20/20 vision in both eyes without correction
    • D20/50 in one eye and 20/20 in the other

    The general standard requires at least 20/40 acuity in each eye separately, with or without corrective lenses, and at least 70 degrees of horizontal field in each eye. Part 391 also has a separate alternative vision standard for some drivers.

    49 CFR § 391.41(b)(10) · General Knowledge — Vision Requirements · verified 2026-06-30

  7. When must a CDL holder report a traffic conviction in another state to their employer?

    • AWithin 30 days of the convictionCorrect
    • BOnly if the conviction results in license suspension
    • CWithin 10 business days of the conviction
    • DAt the next annual review

    A CDL holder must notify their employer of any traffic conviction (in any vehicle, in any state) within 30 days of the conviction, as required by 49 CFR 383.31.

    49 CFR § 383.31 · General Knowledge — Driver Reporting Responsibilities · verified 2026-06-30

  8. When driving in freezing conditions, what does “black ice” mean?

    • AIce that appears black due to oil contamination on the road
    • BA thin, nearly transparent layer of ice that looks like wet roadCorrect
    • CIce that forms only on black asphalt
    • DIce visible only at night

    Black ice is a thin, nearly transparent layer of ice that takes on the appearance of the pavement beneath it. It is extremely slippery and difficult to see, making it especially hazardous.

    FMCSA CDL Testing System — General Knowledge · General Knowledge — Weather Hazards · verified 2026-06-30

  9. Why should a driver turn off a retarder on a wet, icy, or snow-covered road?

    • AThe drive wheels can lose traction and skidCorrect
    • BThe retarder will inflate the tires
    • CThe retarder will disconnect the trailer
    • DThe retarder will raise the landing gear

    A retarder can cause the drive wheels to lose traction on wet, icy, or snow-covered roads. Turn it off in slippery conditions and use braking inputs appropriate to the available traction.

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

  10. Which statement about retarder use on a slippery surface is false?

    • AUsing a retarder on slippery surfaces can cause drive wheel lockup and loss of control
    • BRetarders should be turned off in wet, icy, or snowy conditions
    • CRetarders can cause jackknifing on slippery roads
    • DRetarder use is always acceptable regardless of road conditionsCorrect

    Retarders should be turned OFF on wet, icy, or snowy roads. Retarder braking force on the drive wheels can cause wheel lockup and jackknifing on slippery surfaces.

    FMCSA CDL Testing System — General Knowledge · General Knowledge — Retarder Cautions · verified 2026-06-30

  11. What is the primary danger of driving in the 'No-Zone' of a large truck?

    • AThe truck driver may not be able to see your vehicle in these blind spotsCorrect
    • BIt creates excessive air turbulence that damages your vehicle
    • CThe air pressure from the truck will cause you to merge into traffic
    • DIt is illegal to drive in the no-zone under federal law

    The No-Zone areas (directly in front, behind, and on the sides of a CMV) are large blind spots where the truck driver has very limited or no visibility of surrounding vehicles.

    FMCSA CDL Testing System — General Knowledge · General Knowledge — No-Zones · verified 2026-06-30

  12. What is 'brake fade' and what causes it?

    • AThe decrease in braking caused by worn brake pads, a separate wear issue distinct from heat-related fade
    • BThe vibration in the steering wheel when brakes are applied at high speed
    • CThe pulling to one side caused by uneven brake adjustment
    • DThe loss of brake performance due to overheating of the brake drums and linings after extended or repeated hard brakingCorrect

    Brake fade occurs when brakes are applied repeatedly or for extended periods (such as on a long downgrade), causing drums and linings to overheat. Reduced friction between hot metal surfaces dramatically reduces braking effectiveness.

    FMCSA CDL Testing System — General Knowledge · General Knowledge — Brake Fade · verified 2026-06-30

  13. Which approach checks both resistance to separation and correct fifth-wheel engagement before a trip?

    • ADo a gentle tug with trailer brakes locked, then secure the tractor and visually inspect the couplingCorrect
    • BLook from outside without checking the jaws or doing the tug
    • CDrive 50 feet and listen for unusual sounds
    • DCheck only the air hoses

    The gentle pull and the secured visual inspection answer different questions. Inspect the jaws, plates, and locking mechanism as well as testing resistance; connected hoses do not prove a locked fifth wheel.

    Oregon DMV Commercial Driver Manual · 6.2.4 Air-lines; 6.2.5 Hose Couplers; 6.4.1 Coupling; 6.4.2 Uncoupling · verified 2026-09-07

  14. During controlled braking, what should a driver do if the wheels lock or a larger steering correction is needed?

    • ARelease the brakes, then reapply as soon as possibleCorrect
    • BHold maximum pressure and turn sharply
    • CApply the parking brake
    • DAccelerate until the wheels unlock

    Controlled braking uses firm braking without wheel lock. If the wheels lock or a larger steering correction is needed, release the brakes and reapply them as soon as possible after control returns.

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

  15. You are driving in heavy traffic and the vehicle ahead suddenly stops. What is the safest action?

    • AApply maximum braking force immediately, risking wheel lockup and loss of steering control
    • BApply controlled braking with maximum force that avoids wheel lockup while checking mirrors for escape routesCorrect
    • CSwerve to an adjacent lane without checking mirrors
    • DFlash high beams to warn the driver behind you

    In a sudden stop situation, apply controlled braking (maximum without locking wheels) while scanning mirrors for an escape path if stopping in time is not possible. Swerving without a mirror check creates a new hazard.

    FMCSA CDL Testing System — General Knowledge · General Knowledge — Crash Avoidance · verified 2026-06-30

  16. What is the effect of doubling your speed on your vehicle's braking distance?

    • AIt doubles the braking distance
    • BIt triples the braking distance
    • CIt has no effect — modern ABS compensates for speed
    • DIt quadruples the braking distanceCorrect

    Braking distance is proportional to the square of your speed. If you double your speed, your braking distance increases by a factor of four (quadruples). This is why speed control is critical for CMV safety.

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

  17. What is the minimum number of tie-downs required for cargo that is 10 feet long?

    • A2Correct
    • B1
    • C3
    • D4

    Under 49 CFR 393.102, cargo must have at least one tie-down per 10 feet of cargo length (or fraction thereof), with a minimum of two tie-downs for any load. A 10-foot load requires at least 2 tie-downs.

    49 CFR § 393.102 · General Knowledge — Cargo Securement · verified 2026-06-30

  18. Which type of fire extinguisher is recommended for use on electrical fires in a CMV?

    • AWater extinguisher (Class A)
    • BFoam extinguisher (water-based)
    • CA Class D agent intended for combustible-metal fires
    • DCO2 or dry chemical (non-water type)Correct

    Do not use a water-based extinguisher on an energized electrical fire. A CO2 or non-water dry-chemical extinguisher is the suitable type listed for that hazard.

    FMCSA CDL Testing System — General Knowledge · General Knowledge — Fire Extinguisher Types · verified 2026-06-30

  19. What does the FMCSA manual say about air drag in modern trucks?

    • AAir resistance decreases linearly with speed — doubling speed halves resistance
    • BStreamlined shapes reduce air drag and help fuel economyCorrect
    • CAir resistance only affects vehicles over 80,000 lbs
    • DAir resistance is offset by the wake behind the tractor and has minimal effect

    The FMCSA manual notes that modern trucks use streamlined shapes for fuel economy and have less air drag. It does not establish a universal percentage or speed law for fuel use.

    FMCSA CDL Testing System — General Knowledge · General Knowledge — Fuel Economy · verified 2026-06-30

  20. What action should you take if your steering suddenly becomes very difficult (power steering failure)?

    • AImmediately stop by slamming on the brakes
    • BApply the parking brake to help slow down
    • CContinue driving at reduced speed since it is still steerable
    • DSlow gradually, keep both hands on the wheel, and pull offCorrect

    If power steering fails, the vehicle can still be steered but it will require significantly more effort. Reduce speed gradually, keep both hands on the wheel, and safely exit the road. Do not continue driving with a failed power steering system.

    FMCSA CDL Testing System — General Knowledge · General Knowledge — Steering Failure · verified 2026-06-30