Oklahoma CDL General Knowledge flashcards
Oklahoma CDL General Knowledge · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Total stopping distance
- The sum of perception distance, reaction distance, brake lag distance, and braking distance. At 55 mph a loaded rig needs roughly the length of a football field to stop.
- Perception distance
- The distance traveled during the time it takes to recognize a hazard, about 3/4 second. At 55 mph this is roughly 60 feet before any braking begins.
- Air brake lag
- The delay between pressing the brake pedal and the brakes actually applying, about 3/4 second. At 55 mph the vehicle travels about 60 feet before braking force begins.
- 4-second rule
- A following-distance rule for vehicles under 40 feet: stay at least 4 seconds behind the vehicle ahead. Add one second above 40 mph and one more in bad weather.
- Tiedown aggregate WLL
- For cargo not requiring a specific securement method, the combined working load limit of all tiedowns must be at least 50 percent of the cargo weight.
- Cargo tiedown count
- Articles 5 feet or shorter and 1,100 pounds or less need one tiedown; longer or heavier articles need two; cargo longer than 10 feet needs at least four.
- Cargo inspection interval
- Inspect cargo and tiedowns within the first 50 miles of travel, then every 150 miles, every 3 hours, or at every change of duty status, whichever comes first.
- Rear overhang marking
- Loads extending 4 feet or more beyond the rear must be marked with an 18-inch red flag by day; at night a red light visible for 500 feet is required.
- Air pressure build test
- With the engine at fast idle (600-900 rpm), pressure must build from 85 to 100 psi within 45 seconds. A longer time suggests a leak or worn compressor.
- Air leakage limits
- With the engine off and brakes released, pressure may drop no more than 3 psi per minute (single) or 4 psi (combination). With brakes applied, 4 psi or 6 psi.
- Low-air warning
- The buzzer and light must activate before pressure drops below 60 psi. The spring brakes then apply automatically between 20 and 45 psi.
- Governor cut-out
- The pressure at which the compressor stops pumping, typically 120-125 psi. Cut-in is typically 100 psi, when the compressor restarts.
- Tractor protection valve
- A valve that closes and applies trailer spring brakes when air pressure drops to 20-45 psi, protecting the tractor's air supply from loss.
- Trailer hand valve
- The johnson bar, used only to test trailer brakes. It must never be used for parking; the parking brake holds the vehicle.
- Fifth wheel coupling check
- Pull the tractor gently forward with the trailer brakes locked. The trailer should not move and the tractor should not pull free; the jaws must be locked around the kingpin.
- Off-tracking
- The tendency of a combination vehicle's rear wheels to follow a shorter path than the front wheels in a turn. A 55-foot trailer can off-track 3-5 feet.
- Seven-step inspection
- A pre-trip inspection covering vehicle overview, engine compartment, walk-around, lights, brake check, and in-cab items. Check fluids, belts, tires, and brakes.
- Tire tread minimum
- Front steer tires need at least 4/32 inch of tread depth; all other tires need at least 2/32 inch. Inspect for cuts, bulges, and proper inflation.
- Slack adjuster check
- With the brakes released, pull each slack adjuster by hand; it should not move more than about 1 inch. Excessive movement indicates adjustment is needed.
- Parking on a grade
- Set the parking brake and chock the wheels. Turn the front wheels toward the curb when facing downhill and away from the curb when facing uphill.
- GOAL method
- Get Out And Look. When backing or unsure about clearance, stop and walk around the vehicle to check the path before proceeding.
- Downgrade braking
- Select a lower gear before starting down the grade and use engine braking. Do not ride the brakes, which can overheat and fade.
- Double-clutching
- Press the clutch, shift to neutral, release the clutch, press the clutch again, and shift to the next gear. Used to match engine and transmission speed.
- Coasting in neutral
- Coasting in neutral or with the clutch depressed is unsafe; you lose engine braking and control. Stay in gear and use engine braking on grades.
- Tachometer shifting
- Shift up before the engine reaches the governed rpm and downshift before it drops below the torque range. Matching engine speed prevents lugging and over-revving.
- Scanning ahead
- Keep your eyes moving and look 12-15 seconds ahead, about a quarter mile at highway speed. Check mirrors every 5-8 seconds.
- Signaling distance
- Signal at least 100 feet before turning or changing lanes. Use four-way flashers when stopped or moving slowly to warn other drivers.
- Night driving lights
- Dim high beams when meeting or following another vehicle. Use low beams in fog, rain, or snow, because high beams reflect back and reduce visibility.
- Railroad crossing stop
- Stop at least 10 feet from railroad tracks. If carrying hazardous materials, stop 15-50 feet from the tracks and check for trains before crossing.
- Work zone speed
- Reduce speed in construction zones and obey flaggers. Fines are doubled in work zones in Oklahoma, and workers may be present near the travel lane.
- Hazmat shipping papers
- Shipping papers must be within reach while driving and must identify the hazard class and UN number. Placards must match the hazard class on all four sides.
- Emergency warning triangles
- Place warning triangles 10 feet, 100 feet, and 200 feet behind the vehicle. On a divided highway, place them 100 feet, 200 feet, and 500 feet behind.