AK CDL General Knowledge key terms

A systematic examination of a commercial vehicle's critical parts and systems, performed by the driver before each trip, to confirm the vehicle is safe to operate and meets federal and state requirements.

The outside portion of the pre-trip inspection in which the driver moves around the vehicle checking lights, tires, brakes, coupling devices, fluid leaks, and body damage from ground level.

A standard sequence for pre-trip checks covering the previous inspection report, engine compartment, cab interior, exterior lights, brake system tests, and final signal and brake operation checks before driving.

With the engine off and the system fully charged, the driver releases the parking brake and watches the gauge for a pressure drop greater than the allowed rate, which signals a leak.

The distance an air brake chamber's pushrod extends when the brake is applied; measuring it against the legal limit shows whether the slack adjuster and brakes are properly adjusted.

The depth of the grooves on a tire; worn tread lengthens stopping distance and raises hydroplaning risk, so drivers measure it during the walk-around and remove tires below the legal minimum.

The fire extinguisher, warning triangles or flares, and spare fuses a commercial vehicle must carry; the driver checks that each item is present, charged, and ready for use.

A shifting technique for non-synchronized transmissions in which the driver disengages the clutch, shifts to neutral, releases the clutch, then presses it again to engage the next gear without grinding.

Upshifting at the lowest engine speed that still produces adequate power, keeping the engine in its efficient range so the driver uses fewer revolutions, saves fuel, and reduces wear.

The tendency of a vehicle's rear wheels to follow a tighter path than the front wheels in a turn, requiring the driver to swing wide and watch the trailer's rear near curbs and poles.

Backing toward the driver's right, where the trailer blocks most of the view. It is the highest-risk backing maneuver and should be avoided or performed with a spotter.

A person outside the vehicle who directs a backing maneuver with hand signals and stays visible in the mirrors; the driver must stop immediately if the spotter disappears from view.

Areas around a truck the driver cannot see in the mirrors, including directly behind, alongside the cab, and in front of the hood, where other road users can vanish from view.

Setting flat and convex mirrors so the driver can see the vehicle's sides, the trailer wheels, and the adjacent lane, shrinking blind spots before the vehicle moves.

How far ahead a driver scans the road, roughly twelve to fifteen seconds at highway speed, which gives time to identify hazards and plan a smooth response instead of reacting suddenly.

Keep a gap of at least one second for every ten feet of vehicle length below 40 mph, adding one second above that, timed as the vehicle ahead passes a fixed object.

The sum of perception distance, reaction distance, and braking distance. It grows with speed and weight, and on slippery pavement the braking portion can multiply several times over.

The buffer of empty roadway kept around the vehicle on all sides so the driver has room to stop or steer away when traffic slows or a hazard appears.

A graded gravel or sand off-ramp built for runaway trucks on long downgrades; a driver who has lost braking control steers onto it and lets the soft surface slow the vehicle.

An emergency braking method for vehicles without antilock brakes: apply the brake fully, release when the wheels lock, and reapply, repeating until the vehicle comes to a stop.

The cornering force at which a vehicle tips instead of slides; a high center of gravity and fast turns lower it, so drivers slow before curves and keep loads low and centered.

The procedure for returning to the pavement after wheels leave the road: hold the wheel firmly, slow gradually, and steer back gently once speed is low enough to avoid a sharp swerve.

A loss of control in which the tractor and trailer fold toward each other at a sharp angle, usually from overbraking or abrupt steering on slick pavement, and often unrecoverable past a certain angle.

A thin, nearly invisible ice layer on the road, common on bridges, shaded curves, and after freezing rain in Alaska, offering almost no traction while looking like wet pavement.

An electronic system that rapidly releases and reapplies brake pressure to prevent wheel lockup, helping the driver keep steering control during hard stops on slippery surfaces.

A buzzer and light that activate when brake system air pressure drops below roughly 60 psi, warning the driver to stop safely before the spring brakes apply automatically.

Heavy-duty parking brakes held released by air pressure and applied by strong springs when pressure is lost, so a serious air leak brings the vehicle to a controlled stop.

Gross vehicle weight rating: the maximum total weight of a single vehicle including its own weight, fuel, passengers, and cargo, set by the manufacturer and never to be exceeded.

The sum of the working load limits of all tiedowns on a load; rules require enough tiedowns and combined strength to hold cargo against forward, rearward, and sideways forces.

A federal equation limiting the weight carried on any group of axles based on the number of axles and the distance between them, protecting bridges from concentrated heavy loads.

A strong barrier at the front of a flatbed or trailer that stops cargo from sliding forward into the cab during a sudden stop or crash.

Written authorization to move a vehicle or load exceeding legal size or weight limits, naming the allowed route and conditions; operating without one can bring fines and an order to stop.

A property-carrying driver may drive no more than 11 hours after 10 consecutive hours off duty, and may not drive beyond the 14th consecutive hour after coming on duty.

After eight cumulative hours of driving without at least a 30-minute interruption, a driver must take a 30-minute break before driving again; on-duty not driving time can count.

A device that automatically records driving time and engine data, replacing paper logs for most drivers and helping inspectors verify hours-of-service compliance at roadside.

A bump or ridge formed when freezing soil expands and pushes the road surface upward, common on Alaska highways in winter and spring; drivers must slow down to keep control.

The danger of striking a moose, which stands tall on thin legs and often comes over the hood; Alaska drivers scan shoulders, slow at dawn and dusk, and watch for several animals together.

Winter tires with metal studs that bite into ice, permitted in Alaska during the winter months; they improve traction on frozen roads but do not replace reduced speed.

A remote gravel and paved haul road north of Fairbanks serving the oil fields, with long gaps between services, heavy truck traffic, and extreme winter conditions that demand extra planning.

A rule requiring certain vehicles to install tire chains on posted steep or icy grades in Alaska before proceeding; drivers should carry chains and practice installing them in advance.