Ohio CDL General Knowledge flashcards

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

CDL Class A

A combination vehicle with a gross combination weight rating of 26,001 lb or more, including a towed unit over 10,000 lb. It permits driving Class B and Class C vehicles with proper endorsements.

CDL Class B

A single vehicle with a gross vehicle weight rating of 26,001 lb or more, or any such vehicle towing a unit of 10,000 lb or less. It also covers Class C vehicles with the right endorsements.

CDL Class C

A single vehicle rated 26,000 lb or less that carries 16 or more passengers, including the driver, or carries placarded amounts of hazardous materials. It does not cover Class A or B vehicles.

Ohio height limit

The maximum legal vehicle height in Ohio is 13 feet 6 inches. Loads above this need an oversize permit, and the driver must check low clearances along the planned route.

Ohio width limit

The maximum legal width is 8 feet 6 inches, measured at the widest point including mirrors and load overhang. Wider loads require a permit and often escort vehicles.

Total stopping distance

The sum of perception distance, reaction distance, brake lag distance, and braking distance. At 55 mph it is about the length of a football field on dry pavement.

Speed and stopping distance

Stopping distance increases with the square of speed. Doubling speed from 30 to 60 mph roughly quadruples the braking distance, so a safe following gap must grow as speed rises.

CDL alcohol limit

A commercial driver is considered under the influence at 0.04% blood alcohol concentration while operating a commercial motor vehicle. The limit is 0.08% in a personal vehicle and 0.02% for drivers under 21.

Test refusal penalty

Refusing a chemical test after a lawful request results in a one-year CDL disqualification for a first offense. A second refusal brings a lifetime disqualification under federal rules.

11-hour driving limit

A property-carrying driver may drive no more than 11 hours after 10 consecutive hours off duty. Driving beyond that point is a violation even if the driver feels alert.

14-hour window

A driver may not drive after the 14th consecutive hour since coming on duty, following 10 hours off. Off-duty breaks do not extend the window, though they do not count as driving time.

30-minute break rule

After 8 cumulative hours of driving without at least a 30-minute interruption, a property-carrying driver must take a 30-minute break. It may be off-duty, sleeper berth, or on-duty not driving.

34-hour restart

A driver may reset the 60-hour/7-day or 70-hour/8-day cycle by taking 34 or more consecutive hours off duty. The reset restarts both weekly limits.

Brake out-of-service rule

A vehicle is placed out of service when 20% or more of its brakes are defective, or when any defect exists on a steering-axle brake. The defect must be repaired before driving.

Following distance rule

Below 40 mph, allow one second for each 10 feet of vehicle length. Above 40 mph, add one extra second. Add more space in rain, darkness, or heavy traffic.

Off-tracking in turns

Rear wheels follow a shorter path than front wheels, cutting the corner by roughly 2 to 3 feet for every 10 feet of wheelbase. Drivers must check mirrors and swing wide without crossing the centerline.

Stab braking

On a long downgrade, apply the brakes firmly until the vehicle slows, release when wheels nearly stop, and repeat. This lets brakes cool and avoids continuous drag that causes fade.

Engine braking on grades

Select a gear low enough to hold a safe speed before starting down a grade. Use engine braking with intermittent wheel braking; never coast in neutral or rely on brakes alone.

Hydroplaning speed

Hydroplaning can begin at speeds as low as 30 mph on wet pavement, especially with worn tires or light loads. Ease off the accelerator and avoid hard braking or sharp steering.

Front tire blowout

Hold the wheel firmly and keep the vehicle straight. Accelerate briefly to transfer weight rearward, then ease off and let the vehicle slow before braking gently to a stop.

Railroad crossing rules

Never stop on tracks, and do not shift gears while crossing. If the vehicle stalls, get everyone out and away from the tracks before a train arrives.

Dimming high beams

Dim high beams within 500 feet of oncoming traffic and within 200 feet when following another vehicle. At night, drive at a speed that lets you stop within the lit distance.

Tiedown requirement

Cargo needs at least one tiedown for every 10 feet of article length, with a minimum of two. The combined working load limit must be at least half the cargo weight.

Aggregate working load limit

The sum of the working load limits of all tiedowns used on a load. It must equal at least 50% of the cargo weight for most loads to meet federal securement rules.

Rear overhang flag

A load extending more than 4 feet beyond the rear of the vehicle needs a red flag by day and a red light at night. Loads may not extend more than 4 feet past the front bumper.

Axle weight limits

Federal limits are 20,000 lb on a single axle, 34,000 lb on a tandem axle group, and 80,000 lb gross vehicle weight. The bridge formula also restricts weight based on axle spacing.

Steering tire tread

Front steering tires must have at least 4/32 inch of tread depth. All other tires need at least 2/32 inch. Tires with cuts, bulges, or exposed cords are out of service.

Slack adjuster check

With brakes released, push the slack adjuster by hand. Movement of more than about 1 inch means the brake is out of adjustment and the vehicle must not be driven until repaired.

Low air pressure warning

The warning buzzer or light must activate before air pressure drops below 60 psi. Spring brakes should apply automatically between 20 and 45 psi, stopping the vehicle.

Governor cut-out pressure

The air compressor stops building pressure near 120 to 125 psi and restarts around 100 psi. A gauge that never reaches cut-out indicates a compressor or leak problem.

Placard threshold

Placards are required for any amount of a Table 1 hazardous material and for 1,001 lb or more of a Table 2 material. A placarded load requires the hazmat endorsement.

Post-trip inspection report

The driver completes a written report at the end of each day listing defects found. The next driver must review and sign it before operating the vehicle.