DMV CDL Test (Version 4)

General Knowledge

• Convex mirrors provide a wider field of view compared to flat mirrors.
• Activate 4-way emergency flashers when parked on the roadside at night to alert others.
• For exiting highways on a downhill curve, slow down before entering the curve.
• Rust around wheel fasteners indicates they may be loose.
• Poor traction on drive wheels can lead to skidding when retarders are used.
• Large vehicles require larger gaps in traffic for crossing compared to smaller vehicles.
• Cold medicines can cause drowsiness and should not be used before driving.
• Brake fade occurs when brakes overheat due to excessive use.
• To cool a burning tire, use water.
• Automatic transmissions do not offer extra gears on some trucks.
• Always downshift before entering a curve for better control.
• Forcing an automatic transmission into a lower gear at high speed does not lead to loss of steering control.
• Avoid backing up with heavy vehicles whenever possible.
• Look approximately one block ahead at low speeds while driving.
• Use your horn to prevent potential crashes.
• Be aware that mirrors cannot show all blind spots.
• Do not leave high beams on if headlights are malfunctioning.
• Remove ice from radiator shutters for proper functioning.
• Use 4-way flashers or brake lights to warn others of road hazards.
• In traffic emergencies, it’s typically easier to steer around obstacles than to stop quickly.
• If hydraulic brake pedals go to the floor, pumping the brakes may restore pressure.
• Hydroplaning occurs in conditions of excessive water on the roadway.
• Bridge formula regulations require less axle weight for closely spaced axles.
• Hazardous materials are identifiable by their labels.
• Reflective triangles must be placed within 500 feet behind a vehicle stopped on a hill or curve.
• Taking short breaks during driving helps maintain alertness.
• Balanced hours of service with adequate sleep is essential for driver alertness.
• Regular breaks for rest and exercise can help prevent fatigue on long trips.
• Take breaks before feeling sleepy to remain focused while driving.
• Rising Blood Alcohol Concentration (BAC) negatively impacts judgment and self-control.
• A detectable BAC below 0.04% will result in being placed out-of-service for 24 hours.
• Never remove the radiator cap from a hot system to avoid injury.
• On icy roads, stop driving as soon as safely possible.
• When making a left turn with a long vehicle, use the leftmost lane (lane B) whenever possible in a multiple-lane setting.
• Use windshield washer antifreeze in cold weather to maintain visibility.
• Be cautious of short-term rental truck drivers as they may lack experience with vehicle dimensions.
• Shoulders on roads may not support the weight of large vehicles, so be mindful when leaving the roadway.
• During emergency braking, skidding wheels result in loss of vehicle control.
• Proper cargo blocking should be utilized in all areas of the cargo.
• Regular vehicle inspections are crucial for ensuring safety.

Brake Systems

• To prevent brake fade on steep downgrades, select an appropriate gear for safe vehicle speed.
• After consuming alcohol, allow adequate time for it to leave your system before driving.
• Sleep debt can only be paid off with sleep.
• If feeling sleepy after hours of driving, park safely and take a nap.
• Tire air pressure increases as temperature rises.
• Always use a helper when backing up a vehicle to ensure safety.
• Dirt roads can pose dangers when crossing railroad tracks, including potential get-hung situations.
• Knowledge of HazMat regulations doesn't require expertise in basic chemistry.
• Drug use increases the likelihood of collisions and legal issues.
• At night, dim headlights when oncoming vehicles are within 500 feet.

Air Brakes

• Engage the parking brake every time you leave your vehicle unless exceptions apply.
• Vehicles manufactured after 1998 come equipped with anti-lock braking systems (ABS).
• Brakes in steep downgrades work alongside engine braking for better control.
• Dual air brake systems have a primary and secondary system, often operating different axles.
• Draining air storage tanks is necessary to prevent oil and water buildup that can lead to brake failure.
• Safety valves protect the air brake system from over-pressurization, usually set to open at around 150 psi.
• A slack adjuster should not move more than one inch when pulled hard.
• If air pressure drops below regulations in a dual system, stop the vehicle immediately.
• Daily checks in cold weather should include alcohol evaporator levels if applicable.
• Brake fade can occur due to excessive reliance on service brakes or improper adjustment.
• One-way check valves in the air compressor prevent air from escaping the tank.

Combination Vehicles

• When uncoupling a loaded trailer, ensure landing gear contacts the ground firmly.
• After connecting air lines, supply air to the trailer system before backing up.
• Keeping cargo low and driving slowly around turns helps prevent rollovers.
• The type of vehicle most prone to off-tracking is a 5-axle tractor towing a 53-foot trailer.
• Elevator supports must be fully raised and secure before driving away after coupling.
• An unlocked fifth wheel after aligning indicates a faulty coupling that must be corrected.
• Ensure no space exists between the upper and lower fifth wheels upon coupling.
• Combination vehicles have more inspection points compared to straight trucks.
• Raise landing gear using high gear after coupling to ensure proper securing.
• Always use low reverse gear when backing a tractor under a trailer to minimize risks.
• Attempting to couple with a trailer that is too high may result in improper coupling.
• Applying the hand brake is not advised to correct a jackknifing trailer.
• ABS does not enhance normal braking ability; it helps prevent loss of control.
• Identification of trailers with ABS typically does not include labeling on the steering wheel.
• After unlocking the fifth wheel during uncoupling, pull the tractor forward to clear the trailer.

Driving Doubles and Triples

• Maintain an 11-second following distance while driving a 100-ft twin trailer at 50 mph on dry roads.
• Doubles and triples require smooth driving to prevent rollover or jackknife situations.
• Secure a second trailer using its emergency air brakes when coupling.
• Ensure the pintle hook is latched during inspections of coupled doubles and triples.
• Follow correct shut-off valve positions to ensure safe air distribution in coupled trailers.
• A normal tractor trailer's safe speed on curves may exceed safe levels for doubles or triples.
• A trailer may jackknife if trailer wheels skid while driving a set of doubles.
• Check that upper and lower fifth wheels are properly aligned when inspecting a converter dolly.
• Utilize engine braking on downhill drives to maintain optimal brake temperature and functionality.
• Be aware that quick steering movements can lead to rollovers in doubles or triples.
• The converter dolly air tank petcocks should be closed for safe functioning during travel.
• Compared to tractor semi-trailers, double and triple trailers have a higher likelihood of turning over.
• Slow down when dimming headlights at night to manage speed effectively.