CDL General Knowledge — All Questions

After taking 10 consecutive hours off duty, what is the maximum number of hours a property-carrying driver may drive?

• a.14 hours
• b.11 hours✓
• c.10 hours
• d.12 hours

A property-carrying driver may drive up to 11 hours after 10 consecutive hours off duty. The 14-hour figure is the on-duty window inside which that driving must be completed, and 10 and 12 hours are not the driving limit.49 CFR §395.3

You came on duty at 6:00 a.m. after 10 hours off. Ignoring any exceptions, what is the latest time you may still be driving?

• a.10:00 p.m.
• b.6:00 p.m.
• c.5:00 p.m.
• d.8:00 p.m.✓

The 14-hour window runs from the moment you come on duty, so driving must end by 8:00 p.m., and off-duty breaks do not extend it. Ending at 5:00 or 6:00 p.m. is earlier than required, and 10:00 p.m. is four hours past the limit.49 CFR §395.3

When must a property-carrying driver take the required 30-minute break?

• a.Every 2 hours of driving
• b.After 10 hours on duty
• c.Before driving more than 8 cumulative hours without at least a 30-minute interruption of driving time✓
• d.After 4 hours on duty

The rule triggers on 8 cumulative hours of driving time and can be satisfied by any 30 consecutive minutes not spent driving. It is not tied to 4 or 10 hours on duty, and there is no requirement to break every 2 hours.49 CFR §395.3

Your carrier operates every day of the week. Which on-duty limit applies to you?

• a.70 hours in any 8 consecutive days✓
• b.60 hours in any 7 consecutive days
• c.80 hours in any 8 consecutive days
• d.50 hours in any 6 consecutive days

Carriers operating seven days a week use the 70-hour, 8-day limit, while the 60-hour, 7-day limit applies to carriers that do not operate every day. The 50-hour and 80-hour figures are not federal limits.49 CFR §395.3

You have reached your 70-hour limit. How can you reset your available hours under the restart provision?

• a.Take 34 or more consecutive hours off duty✓
• b.Take two separate 12-hour breaks
• c.Wait until the start of the next calendar month
• d.Take 24 consecutive hours off duty

The optional restart requires at least 34 consecutive hours off duty, after which the 60 or 70-hour count begins again. A 24-hour break, split breaks, and calendar changes do not reset the weekly total.49 CFR §395.3

You encounter unexpected snow that was not forecast when you dispatched, which slows your trip badly. What relief does the adverse driving conditions exception provide?

• a.It waives the requirement to keep records for that day
• b.Up to 2 additional hours of driving time and 2 additional hours of the 14-hour window to complete the run or reach a safe place✓
• c.Unlimited driving time until the load is delivered
• d.Four additional hours of driving time

The exception adds up to two hours of driving time and extends the driving window by the same two hours when conditions could not have been known before dispatch. It is not unlimited, is not four hours, and never removes the duty to record hours.49 CFR §395.1

What is the purpose of an electronic logging device on a commercial motor vehicle?

• a.To replace the requirement to keep any supporting documents
• b.To measure axle weights while driving
• c.To automatically record driving time by connecting to the engine so hours-of-service records are accurate✓
• d.To track fuel purchases for tax reporting only

An ELD synchronizes with the engine to capture driving time automatically, which is why it replaced most paper logs. Fuel tax tracking and weight measurement are separate systems, and drivers must still retain supporting documents.49 CFR §395.8

What blood alcohol concentration makes it unlawful for a CDL holder to operate a commercial motor vehicle?

• a.0.08 or higher
• b.0.02 or higher
• c.0.10 or higher
• d.0.04 or higher✓

The commercial limit is 0.04, half the 0.08 limit that applies to most non-commercial drivers. A driver found at 0.04 or above, or with any detectable alcohol, is placed out of service for 24 hours.49 CFR §392.5

You are stopped at a roadside inspection and test at 0.02 blood alcohol concentration. What happens?

• a.Your CDL is revoked permanently on the spot
• b.Nothing, because you are below 0.04
• c.You are cited but may continue driving
• d.You are placed out of service for 24 hours because any detectable alcohol prohibits operation✓

Having any measured alcohol concentration while on duty triggers a 24-hour out-of-service order even below the 0.04 threshold that carries heavier penalties. Continuing to drive is prohibited, and a permanent revocation is not the immediate roadside consequence.49 CFR §392.5

A CDL holder refuses to submit to required alcohol testing after a crash. What is the consequence?

• a.Disqualification for at least one year, the same as a first conviction for driving under the influence✓
• b.A written warning only
• c.A 30-day suspension
• d.A fine with no effect on the license

Refusal is treated exactly like a positive test, resulting in disqualification for at least one year, or three years if the driver was transporting placarded hazardous materials. Warnings, fines alone, and short suspensions do not reflect the federal penalty.49 CFR §383.51

A CDL holder is convicted a second time of driving a vehicle under the influence. What is the disqualification?

• a.Life, though reinstatement may be possible after 10 years in some cases✓
• b.One year
• c.Three years
• d.Sixty days

A second major offense results in lifetime disqualification, with limited reinstatement possible after 10 years under a state-approved program. One year is the first-offense penalty, three years applies to a first offense while hauling placarded hazmat, and 60 days relates to serious traffic violations.49 CFR §383.51

You are convicted of two serious traffic violations, such as excessive speeding and reckless driving, in separate incidents within a three-year period. What is the result?

• a.Disqualification for one year
• b.Disqualification for 60 days✓
• c.A warning letter only
• d.No effect unless a crash occurred

Two serious traffic violations in three years bring a 60-day disqualification, and a third within the same period brings 120 days. A warning is not the penalty, one year applies to major offenses, and a crash is not required for the disqualification to apply.49 CFR §383.51

You are driving on the interstate and your phone rings. What does federal regulation allow?

• a.Using a hands-free device that requires no more than a single push of a button, with the phone located where you can reach it while belted✓
• b.Holding the phone while using speakerphone
• c.Reading and sending short text messages at a stoplight
• d.Answering by holding the phone to your ear if the call is brief

Federal rules ban holding a mobile phone and ban texting while driving a commercial vehicle, allowing only hands-free operation with a single touch. Brief handheld calls, texting while temporarily stopped in traffic, and holding a phone on speaker all violate the rule.49 CFR §392.82

What is the penalty exposure for a CDL holder convicted of texting while driving a commercial motor vehicle?

• a.Loss of the medical certificate
• b.A verbal warning from the officer
• c.Immediate lifetime disqualification
• d.Substantial civil penalties, and disqualification for 60 days after two convictions in three years or 120 days after three convictions✓

Texting is classified as a serious traffic violation, so repeat convictions bring the 60-day and 120-day disqualifications along with civil penalties for drivers and employers. A warning understates the consequence, medical certification is unrelated, and lifetime disqualification is reserved for major offenses.49 CFR §392.80

How long is a standard medical examiner's certificate valid for an interstate commercial driver with no disqualifying conditions?

• a.Up to 24 months✓
• b.Up to 36 months
• c.Up to 12 months
• d.It never expires once issued

A standard certificate is valid for a maximum of 24 months, and the examiner may issue a shorter certificate when a condition requires monitoring, such as one year for controlled hypertension. Twelve and 36 months are not the standard maximum, and every certificate expires.49 CFR §391.45

You are two hours from your delivery when you realize you are struggling to stay awake and have drifted within your lane. What does the regulation require?

• a.Continue because you still have driving hours available
• b.Stop driving, because a driver whose alertness is impaired by fatigue or illness may not operate a commercial vehicle✓
• c.Continue if you can open a window and drink coffee
• d.Continue but reduce speed by 10 mph

The rule prohibits operating while ability or alertness is impaired by fatigue, illness, or any other cause, regardless of hours remaining. Caffeine, fresh air, and lower speed do not restore alertness, and available hours never authorize driving while impaired.49 CFR §392.3

Which of the following is the most reliable way to prevent driver fatigue?

• a.Turning up the radio and lowering the cab temperature
• b.Drinking energy drinks throughout the run
• c.Taking short naps only after fatigue becomes severe
• d.Getting adequate sleep before the trip and scheduling driving during normal waking hours where possible✓

Only sleep restores alertness, and driving during the body's natural low points such as the early morning hours sharply raises crash risk. Stimulants and sensory tricks mask fatigue temporarily, and waiting until fatigue is severe means you are already impaired.

What does federal regulation require regarding seat belt use in a commercial motor vehicle?

• a.The driver must have the seat belt properly restraining them whenever the vehicle is being operated✓
• b.Seat belts are required only when the vehicle is loaded
• c.Seat belts are required only on interstate highways
• d.Seat belts are optional for drivers with more than five years of experience

A commercial driver must be properly belted any time the vehicle is in operation, with no exception for experience, road type, or load status. Being thrown from the cab is a leading cause of death in truck crashes, which is why the rule has no exceptions.49 CFR §392.16