NH CDL General Knowledge flashcards
NH CDL General Knowledge · Build recall with a focused review session.
31 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Pre-trip brake leakage limit
- With a fully charged air system, engine off, and brakes released, leakage must not exceed 3 psi per minute for a single vehicle or 4 psi per minute for a combination vehicle.
- Low air pressure warning
- The warning buzzer or light must activate before air pressure drops below 60 psi. If it fails to work, the vehicle must not be driven.
- Steering wheel free play
- Free play should be no more than 10 degrees, roughly 2 inches of movement at the rim of a 20-inch steering wheel.
- Double clutching steps
- Press the clutch, shift to neutral, release the clutch, press it again, then engage the next gear. This matches engine and transmission speed in unsynchronized gearboxes.
- Off-tracking definition
- The rear wheels of a tractor-trailer follow a path inside the front wheels when turning. Longer wheelbases produce greater off-tracking and require a wider swing.
- Backing safety rule
- Use a helper or get out and look before backing. Back toward the driver's side when possible and correct with small steering movements.
- Following distance rule
- Allow at least one second per 10 feet of vehicle length at speeds under 40 mph, plus one extra second. At 40 mph and above, use one second per 10 feet.
- Aim high steering
- Look at least 12 to 15 seconds ahead of the vehicle and check mirrors every 5 to 8 seconds to spot hazards early.
- Space cushion purpose
- Keep space to the front and sides so you have time and room to react. Avoid driving beside another vehicle in its blind spot.
- Total stopping distance formula
- Total stopping distance equals perception distance plus reaction distance plus brake lag distance plus braking distance.
- Brake lag for air brakes
- Air brakes take about 0.4 to 0.5 seconds to apply after the pedal is pressed. At 55 mph that adds roughly 32 to 40 feet before braking begins.
- Speed and braking distance
- Braking distance increases with the square of speed. Doubling speed roughly quadruples the distance needed to stop.
- Drive-wheel skid correction
- Release the accelerator and steer in the direction you want the front of the vehicle to go. Do not apply the brakes during the correction.
- Front-wheel skid correction
- The vehicle will not turn. Release the brake or accelerator to regain steering, then steer where you want the vehicle to go.
- Preventing skids
- Slow down before curves, brake gently, keep the load balanced, and avoid sudden steering or braking inputs that break traction.
- Tire blowout response
- Hold the steering wheel firmly, release the accelerator, and steer straight. Do not brake hard until the vehicle is under control.
- Reflective triangle placement
- Place triangles within 10 minutes at 10 feet, 100 feet, and 200 feet behind the vehicle on a two-lane road; use 100 and 200 feet on a divided highway.
- Vehicle fire response
- Stop, turn off the engine, get everyone out, and move at least 100 feet away. Do not open the hood if the fire is under it.
- Tiedown aggregate strength
- The sum of the working load limits of all tiedowns must be at least half the cargo weight. Cargo must be secured against shifting.
- Cargo overhang limits
- Cargo may not extend more than 3 feet beyond the front or more than 4 feet beyond the rear. Flag the rear extension if it extends 4 feet or more.
- Federal weight limits
- Steer axle 12,000 pounds, tandem axle 34,000 pounds, and gross vehicle weight 80,000 pounds on the Interstate System.
- Spring brake application
- Spring brakes apply automatically when air pressure drops to about 20 to 45 psi. They are held off by air pressure during normal operation.
- Slack adjuster check
- With the brakes applied, the pushrod should move no more than about 1 inch on a standard chamber. More movement indicates adjustment is needed.
- ABS warning light
- If the ABS light stays on, the anti-lock system is not working. Normal brakes still function, but the vehicle may skid on slippery surfaces.
- CDL alcohol limit
- A CDL holder is considered impaired at 0.04 percent BAC. A first offense results in license suspension and disqualification for at least one year.
- Refusing a drug test
- Refusing a required alcohol or drug test results in disqualification for at least one year, the same as a positive test result.
- Alcohol elimination rate
- The body eliminates alcohol at about one drink per hour. Coffee, food, and cold showers do not speed elimination or lower BAC.
- Railroad crossing stop zone
- At a crossing without gates, stop no closer than 15 feet and no farther than 50 feet from the nearest rail. Look both ways and listen.
- Stalled on railroad tracks
- Get out and move away immediately, then call the emergency number posted at the crossing. Do not stay in the vehicle.
- Hours of service limits
- Property-carrying drivers may drive 11 hours after 10 consecutive hours off duty, within a 14-hour on-duty window, and 60 hours in 7 days or 70 hours in 8 days.
- School bus stop rule
- Stop for a school bus with flashing red lights and an extended stop arm unless you are on a divided highway with a median separating the directions.