OR CDL General Knowledge flashcards

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

Pre-trip inspection order

Engine compartment, then walk-around, then in-cab checks, then the brake test. Complete all four stages before moving the vehicle.

Air brake leak-down limit

With the engine off and full pressure, loss must not exceed 3 psi per minute for a single vehicle or 4 psi per minute for a combination vehicle.

Low-air warning threshold

The warning buzzer or light must activate before pressure drops below 60 psi, and the spring brakes must fully engage by 20 to 45 psi.

Air brake buildup rate

With the engine at operating rpm, pressure must rise from 85 to 100 psi within 45 seconds for a combination vehicle with a dual air system.

Stopping distance formula

Total stopping distance equals perception distance plus reaction distance plus brake lag distance plus braking distance. At 55 mph it is roughly 300 feet.

Following distance rule

Below 40 mph, follow at least one second per 10 feet of vehicle length plus one second; at 40 mph and above, add one extra second.

Hazmat placarding threshold

Placards are required for 1,001 pounds or more of a Table 2 material, any amount of a Table 1 material, and 220 pounds of a Table 3 material.

Railroad crossing procedure

Turn on four-way flashers, check for a clear path, use the lowest gear that will cross without shifting, and never shift gears while crossing the tracks.

Cargo tiedown requirement

The aggregate working load limit of tiedowns must be at least 50 percent of the cargo weight, and the system must withstand 0.8 g forward deceleration.

Out-of-service brake condition

Twenty percent or more of brakes defective, any brake with a missing part, or a pushrod stroke beyond the adjustment limit puts the vehicle out of service.

CDL alcohol limit

A CDL holder is considered driving under the influence at a blood alcohol concentration of 0.04 percent or higher, which is lower than the standard limit.

Major offense disqualification

A first major offense such as DUI or leaving the scene of a fatal crash disqualifies for at least one year; a second major offense disqualifies for life.

Serious traffic violation penalties

Two convictions in three years disqualify for 60 days, and three in three years disqualify for 120 days. Excessive speeding is a serious violation.

Hours of service limits

Property-carrying drivers may drive 11 hours within a 14-hour on-duty window after 10 consecutive hours off duty, with a 30-minute break after 8 driving hours.

Required emergency equipment

At least one fire extinguisher rated 10 BC or larger for a bus or hazmat vehicle, spare fuses, and three reflective warning triangles or six fusees.

Skid recovery technique

Stop braking, keep both hands on the wheel, and steer in the direction you want the vehicle to go. Do not turn the wheel sharply.

Mountain descent technique

Select a gear low enough to hold the descent without using the brakes, descend no faster than the ascent speed, and use snub braking to avoid brake fade.

Tire tread rejection limits

Reject tires with tread depth below 4/32 inch on front wheels or 2/32 inch on other wheels, and reject tires with tread separation or sidewall cuts.

Hazardous materials classes

Class 1 explosives, Class 2 gases, Class 3 flammable liquids, Class 4 flammable solids, Class 5 oxidizers, Class 6 toxic substances, Class 7 radioactive, Class 8 corrosives, Class 9 miscellaneous.

Hazmat shipping papers

Papers must show the proper shipping name, hazard class, identification number, total quantity, and emergency response telephone number, and must be within the driver's reach.

Placarded vehicle parking rules

Park at least 5 feet from the traveled portion of the road, do not park within 300 feet of a bridge, tunnel, or open fire, and never within 5 feet of a railroad track.

Coupling and uncoupling sequence

Back under the trailer slowly, listen for the click of the fifth-wheel jaws, tug-test with the trailer brakes set, and connect the emergency line first and disconnect it last.

Night driving beam rules

Dim high beams within 500 feet of an oncoming vehicle or when following within 200 feet, and use low beams in fog, rain, or snow to avoid glare.

Reportable crash reporting

Notify the nearest police authority immediately, and report a hazardous materials release to the National Response Center at 1-800-424-8802 as soon as possible.

Cargo inspection interval

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

Warning device placement

Place reflective triangles within 10 minutes of stopping, at 10 feet, 100 feet, and 200 feet behind the vehicle on a two-lane road.

Hand-held phone prohibition

A CDL holder may not use a hand-held mobile phone while driving, and texting while driving is a primary offense that can lead to disqualification.

Medical certification requirement

A CDL holder must maintain a current medical examiner's certificate, self-certify the type of driving, and meet vision standards of about 20/40 in each eye.

Fifth-wheel coupling check

Confirm the fifth-wheel jaws are locked around the kingpin, the release lever is secured, and the mounting bolts are tight; a gap between apron and fifth wheel indicates improper coupling.

Spring brake operation

Spring brakes apply automatically when air pressure drops to between 20 and 45 psi, and they can be released manually with a release bolt for towing or repair.

Trailer air line identification

The emergency supply line is typically the larger coupler and the service control line the smaller one; crossed lines can cause trailer brakes to drag or fail to release.

Vehicle inspection report

A driver must prepare a written report at the end of each day's work on a vehicle with a defect, and the carrier must repair any defect affecting safe operation before dispatch.