CCDL Permit Prep

General Knowledge · page 6 of 19

General Knowledge questions 101–120

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. The correct technique for descending a long, steep grade is:

    • APump the service brakes repeatedly at full pressure
    • BUse the highest gear and ride the brakes continuously
    • CSelect a gear before the descent that lets engine braking control speed, using service brakes brieflyCorrect
    • DUse the trailer brake only, leaving the tractor's brakes and engine braking unused

    Before starting a steep descent, shift into a low gear (not neutral) so the engine provides braking. Apply the service brakes just hard enough to feel a definite slowdown; when speed is approximately 5 mph below the selected safe speed, release the brakes. The brake application should last about 3 seconds. Repeat as needed.

    FMCSA Commercial Driver's License Manual (2005 CDL Testing System) · Section 2.16.2 and 2.16.4 — Select the Right Gear before Starting Down the Grade; Proper Braking Technique · verified 2026-09-08

  2. According to the CDL manual, what problem do strong winds cause?

    • AThey make it difficult to stay in your laneCorrect
    • BThey reduce engine power
    • CThey lower tire pressure
    • DThey disable the brakes

    The manual says strong winds make it difficult to stay in your lane, usually worse for lighter vehicles and especially bad coming out of tunnels.

    FMCSA Commercial Driver License Manual (July 2014) · Section 2.7.6: Space for Turns / Strong Winds (Section 2 Driving Safely) · verified 2026-09-25

  3. According to the CDL manual, how does the following distance rule change above 40 mph?

    • AAdd 1 second to the one-second-per-10-feet-of-vehicle-length ruleCorrect
    • BSubtract 1 second
    • CIt stays the same at every speed
    • DUse exactly 2 seconds

    The manual says to leave at least one second per 10 feet of vehicle length below 40 mph and add 1 second at greater speeds.

    FMCSA Commercial Driver License Manual (July 2014) · Section 2.7.1: Space Ahead · verified 2026-09-25

  4. According to the CDL manual, when should you use the four-way emergency flashers?

    • AWhen you are driving very slowly or are stoppedCorrect
    • BWhenever you are driving in the rain
    • CWhen exiting a freeway
    • DOnly when driving faster than traffic

    The manual says to use the four-way emergency flashers when driving very slowly or stopped, to warn following drivers.

    FMCSA Commercial Driver License Manual (July 2014) · Section 2.5.1: Signal Your Intentions · verified 2026-09-25

  5. Per the CDL manual's vehicle inspection, which item should you check for?

    • AA properly charged and rated fire extinguisherCorrect
    • BThe trailer's retail sales price
    • CYour passengers' luggage tags
    • DA radio station preset

    The manual's inspection lists emergency equipment including a properly charged and rated fire extinguisher.

    FMCSA Commercial Driver License Manual (July 2014) · Section 2.1: Vehicle Inspection (emergency equipment) · verified 2026-09-25

  6. For a power unit not used to transport hazardous materials, what fire-extinguisher minimum does 49 CFR 393.95 allow?

    • AOne extinguisher rated at least 5 B:C, or two each rated at least 4 B:CCorrect
    • BAny size if kept anywhere in the cab
    • COnly one extinguisher rated at least 10 B:C
    • DA new extinguisher each month regardless of condition

    For this non-hazmat case, the rule allows one 5 B:C extinguisher or two 4 B:C extinguishers. Required extinguishers must be marked with the rating, fully charged, readily accessible, and securely mounted. Placarded hazmat power units need at least 10 B:C.

    Electronic Code of Federal Regulations · 49 CFR 393.95(a)(1)-(4) · verified 2026-09-08

  7. Why must cargo weight be balanced side to side?

    • AIt affects fuel economy, not vehicle stability or handling
    • BIt matters for refrigerated trailers, not dry van freight
    • CSide-to-side balance affects appearance, not how the truck handles
    • DUneven weight can make the vehicle lean or roll over more easilyCorrect

    Uneven side-to-side loading can affect vehicle balance and handling and increase rollover risk, so cargo weight should be distributed evenly.

    FMCSA Commercial Driver License Manual · Cargo balance · verified 2026-09-08

  8. When checking your CDL vehicle before a trip, which item must be secure before you move?

    • ACargo, doors, and emergency equipmentCorrect
    • BThe fuel cap, since spillage is the main pre-trip concern
    • CThe mirrors; other items can be checked once en route
    • DThe radio and dashboard electronics

    A pre-trip inspection must confirm cargo is secured, doors are latched, and required emergency equipment is present and accessible before the vehicle moves. Federal emergency equipment includes a fire extinguisher and stopped-vehicle warning devices. Spare fuses are not federally required, though a carrier may carry them.

    eCFR 49 CFR 393.95 — Emergency equipment on all power units · 393.95(a), (f), and (g); paragraph (b) reserved · verified 2026-09-07

  9. For accessible cargo subject to § 392.9(b), what must the driver inspect within the first 50 miles of the trip?

    • AThe fuel, oil, and washer-fluid levels before the next fuel stop
    • BThe shipping papers, to confirm the load matches the bill of lading
    • CThe tire tread depth and inflation on every axle of the vehicle
    • DThe cargo and its load-securement devices, making needed adjustmentsCorrect

    Inspect the cargo and securement within the first 50 miles and correct problems. The section has exceptions for certain sealed or impracticable-to-inspect loads. This particular duty does not replace other vehicle inspections.

    49 CFR § 392.9 · 392.9(b)(2) first 50 miles; (b)(4) exceptions · verified 2026-09-29

  10. Under federal hours-of-service rules, what is the maximum driving time for a property-carrying driver after 10 consecutive hours off duty?

    • A11 hoursCorrect
    • B8 hours
    • C14 hours of driving
    • D16 hours

    49 CFR 395.3(a)(3) limits a property-carrying driver to 11 hours of driving after 10 consecutive hours off duty. The 14-hour limit in 395.3(a)(2) is the on-duty window, not driving time.

    49 CFR § 395.3 · 395.3(a)(2) 14-hour period; (a)(3) driving time · verified 2026-09-29

  11. When driving a long commercial vehicle, why should you make turns slowly?

    • AIt's a courtesy to other drivers
    • BOff-tracking can cause the rear wheels to cut across curbs or lanesCorrect
    • CIt matters for tight parking-lot maneuvers, not road turns
    • DIt reduces engine wear more than it affects vehicle control, a claim with no basis in fact

    The rear wheels of a long vehicle follow a shorter, tighter path than the front wheels during a turn (off-tracking). Turning too quickly increases this effect and can cause the rear wheels to strike curbs, medians, or adjacent lanes.

    FMCSA Commercial Driver License Manual (July 2014) · Section 2.7.6: Space for Turns · verified 2026-09-25

  12. If a steer tire fails at highway speed, what should you do first?

    • ABrake hard immediately to stop as quickly as possible
    • BSteer sharply away from the side of the failed tire
    • CGrip the wheel firmly and maintain control before brakingCorrect
    • DAccelerate briefly to help stabilize the vehicle's weight transfer

    A steer tire blowout at speed can pull the vehicle sharply to one side. Gripping the wheel firmly and maintaining directional control comes before braking, since sudden hard braking during the initial pull can worsen loss of control.

    FMCSA Commercial Driver License Manual (July 2014) · Section 2.17.4: Tire Failure · verified 2026-09-25

  13. When evaluating a power unit and its trailers together, what does GCWR mean?

    • AGross Cab Weight Requirement
    • BGeneral Cargo Weight Ratio
    • CGross Combination Weight RatingCorrect
    • DGovernment Carrier Weight Rule

    GCWR means Gross Combination Weight Rating. Under 49 CFR § 383.5, it is the greater of the manufacturer's GCWR for the power unit or the sum of the GVWRs or actual gross vehicle weights of the power unit and towed units, whichever produces the highest value.

    49 CFR § 383.5 (current eCFR) · Definitions — Gross combination weight rating (GCWR) · verified 2026-09-08

  14. A commercial driver may legally hold a CDL from:

    • AAs many states as they work in
    • BAny state plus a federal CDL
    • CTwo neighboring states
    • DOnly one state at a timeCorrect

    Federal law allows a driver only one CDL, issued by the home state, so violations follow the driver and cannot be hidden.

    49 CFR § 383.21 · No person may have more than one license · verified 2026-09-08

  15. During normal CMV driving, using a hand-held mobile phone is:

    • AProhibited by federal regulation, subject to limited exceptionsCorrect
    • BAllowed only on highways
    • CAllowed below 30 mph
    • DAllowed for dispatch calls

    Federal rules generally prohibit hand-held mobile-phone use while driving a CMV, subject to limited regulatory exceptions. The restriction reduces physical and visual distraction.

    49 CFR § 392.82 · Using a hand-held mobile telephone · verified 2026-09-08

  16. Federal regulations require a commercial vehicle driver to:

    • AWear a seat belt only on highways
    • BWear a seat belt at all times while the vehicle is movingCorrect
    • CWear a seat belt only in bad weather
    • DUse a seat belt only when carrying passengers

    A buckled driver stays behind the wheel and in control during a crash or hard stop, so the belt must be worn whenever driving.

    49 CFR § 392.16 · Use of seat belts · verified 2026-09-08

  17. Under the general federal vision standard, a CMV driver must have distant visual acuity of at least:

    • A20/60 in the better eye
    • B20/20 in both eyes
    • C20/40 in each eye, with or without correctionCorrect
    • D20/100 with glasses

    The general FMCSA standard requires at least 20/40 acuity in each eye and a 70-degree field of vision. A separate alternative vision standard may apply to a driver who does not meet the better-eye or worse-eye requirement.

    49 CFR § 391.41 · Physical qualifications - vision · verified 2026-09-08

  18. A CMV driver's medical examiner's certificate (DOT medical card) is generally valid for a maximum of:

    • A6 months
    • B5 years
    • C12 months
    • D24 monthsCorrect

    A standard DOT medical card lasts up to 24 months; a driver with certain conditions may be certified for a shorter period.

    49 CFR § 391.45 · Medical examiner's certificate · verified 2026-09-08

  19. In commercial-driver safety guidance, what does the term “No-Zone” describe?

    • AA zone where CDLs are not required
    • BThe large blind areas around a commercial truck where other road users may not be visible to the driverCorrect
    • CA no-parking area at truck stops reserved for CMVs
    • DThe area inside a weigh station

    No-Zones are blind areas in front of, behind, and beside a large truck where other road users may disappear from the driver's view.

    FMCSA Commercial Driver's License Manual · Section 2.6 - Seeing Hazards · verified 2026-09-08

  20. What is included in a commercial vehicle's perception distance?

    • AThe distance traveled while the brakes bring the vehicle to a stop
    • BThe distance the vehicle travels from when you see a hazard until your brain recognizes itCorrect
    • CThe distance from your bumper to the vehicle ahead
    • DThe distance covered during a lane change

    Perception distance is how far you travel from spotting a hazard until your brain identifies it, and it adds to total stopping distance.

    FMCSA Commercial Driver's License Manual · Section 2.6 - Stopping Distance · verified 2026-09-08