California CDL General Knowledge Test flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Following distance rule

For a CMV, allow one second for each 10 feet of vehicle length, plus one extra second above 40 mph. A 60-foot rig at 50 mph needs about 7 seconds.

Total stopping distance

The sum of perception distance, reaction distance, brake lag, and effective braking distance. It increases with speed, weight, and poor traction, so a loaded truck needs more space.

Visual search lead time

Look about 12 to 15 seconds ahead in cities and up to a quarter mile on highways so you can spot hazards, signals, and changing traffic early.

Railroad crossing procedure

Slow down, look and listen, and verify enough space on the far side before crossing. Never stop on the tracks; vehicles carrying hazmat or passengers often must stop.

Night driving visibility

Do not overdrive your headlights. Drive slowly enough to stop within the distance lit ahead, and use low beams in fog, rain, or when following another vehicle.

Aggregate tiedown strength

For most cargo, the combined working load limit of all tiedowns must be at least 50 percent of the cargo weight, and at least two tiedowns are required.

Cargo height limit California

In California, a vehicle and load generally may not exceed 14 feet in height. Check route restrictions because bridges and overpasses may be lower.

Cargo inspection interval

Inspect cargo and tiedowns within the first 50 miles of a trip and every 150 miles or 3 hours afterward, whichever comes first.

Axle weight compliance

Do not exceed Gross Axle Weight Rating, Gross Vehicle Weight Rating, or tire limits. Distribute cargo to keep each axle and the whole vehicle within legal limits.

Cargo covering requirement

Loads that could spill, blow off, or create dust must be covered. Cargo also must not obscure lights, reflectors, plates, or the driver's view.

Pre-trip inspection purpose

A pre-trip inspection checks tires, lights, brakes, fluids, coupling, and cargo before driving. It helps catch defects that could cause breakdowns, crashes, or out-of-service violations.

Air pressure warning threshold

A low-air warning must activate before air pressure drops below 60 psi. Spring brakes normally begin to apply when pressure falls into the 20 to 45 psi range.

Backing safety speed

Back slowly, no faster than a walk. Use mirrors and a spotter when available; stop and recheck if you lose sight of the spotter or the path is unclear.

Parking on a grade

Set the parking brake, place the transmission in a low gear or park, and turn wheels toward the curb when facing downhill. Use wheel chocks when required.

Rear-wheel skid correction

Steer in the direction you want the front of the vehicle to go, and avoid hard braking. Look and steer where you want to travel rather than at the obstruction.

Hydroplaning risk speed

Hydroplaning can begin at speeds as low as 30 mph on wet roads. Reduce speed, avoid sudden steering or braking, and replace worn tires to lower the risk.

Tire blowout response

Hold the steering wheel firmly, keep the vehicle straight, and slow gradually. Avoid hard braking or sudden steering, then move off the road when it is safe.

Brake failure response

Downshift to use engine braking, apply the parking brake gradually, and look for an escape ramp. Pumping may help only if the failure is from wet brakes.

Vehicle fire response

Stop, shut off the engine, get everyone away, and call emergency services. Do not open the hood fully or use water on fuel or electrical fires.

Dual air brake circuits

A dual air brake system has two separate circuits, so a failure in one may still leave partial braking. The system must be tested before driving.

ABS warning lamp meaning

If the ABS lamp stays on, the anti-lock feature is not working. Normal brakes usually remain available, but wheel lockup protection may be reduced.

CMV tire tread minimum

Front tires need at least 4/32 inch tread depth; all other tires need at least 2/32 inch. Tires also must be properly inflated and free of defects.

Fifth wheel coupling check

After coupling, perform a tug test, ensure the locking jaws are closed around the kingpin, and confirm the safety latch is in place.

Oil pressure warning action

If oil pressure drops or the warning light stays on, stop the engine safely and check the problem. Continuing to drive can destroy the engine.

11-hour driving limit

After 10 consecutive hours off duty, a property-carrying driver may drive up to 11 hours. Driving beyond that limit requires a qualifying reset or exemption.

14-hour duty window

A driver may not drive after the 14th consecutive hour on duty. Off-duty breaks do not extend this window, though qualifying sleeper splits can affect it.

30-minute break rule

Drivers must take at least a 30-minute break after 8 cumulative hours of driving without a qualifying interruption. The break may be off duty, sleeper, or non-driving.

60/70-hour limits

A driver may not drive after 60 hours on duty in 7 days or 70 hours in 8 days. A 34-hour restart can reset these weekly limits.

CDL alcohol limit

A commercial driver is considered over the limit at 0.04 percent blood alcohol concentration. Refusing an alcohol test can lead to license suspension and employment consequences.

Handheld phone prohibition

Commercial drivers may not use a handheld mobile phone while driving. Texting is also prohibited, and penalties can include fines and disqualification.

DOT medical certificate

Commercial drivers generally must carry a current DOT medical examiner's certificate or have a valid medical qualification on their license record.

Fatigue countermeasures

Get adequate sleep before driving, take scheduled breaks, and stop when drowsy. Fatigue slows reaction time and judgment much like alcohol does.