Commercial Driver's License (CDL) Passenger Transport, School Bus, and Special Operations Syllabus

What is the correct loading procedure sequence for a school bus stop?

Approach slowly, activate alternating flashing amber lights ~200 ft before the stop, stop with the front bumper at least 10 ft from waiting students, activate red flashing lights and stop arm, then signal students to board only after traffic has stopped.

After a school bus has finished loading and students are seated, what must the driver check before pulling away?

Check all mirrors, count students/verify all who should be aboard are seated, ensure no student is in the danger zone, then deactivate the red lights/stop arm and proceed when safe.

What is the required after-trip inspection for a school bus regarding passengers?

At the end of every route/trip the driver must walk to the back of the bus and check every seat for sleeping children, items left behind, vandalism, or any remaining passengers before securing the bus.

When unloading at a school stop, what should the driver do to ensure all students are clear?

Count students as they leave, ensure they cross at least 10 ft in front in view of the driver, watch that all reach a safe place, count to confirm everyone is clear of the danger zone, and check mirrors before moving.

What should a school bus driver do if a student drops or forgets an object near the bus?

Tell the student to leave it and move to a point of safety out of the danger zone; the driver should not move the bus until accounting for the student, because students who reach under or near the bus are in great danger.

What is the recommended action if a school bus must be evacuated due to a hazard?

Evacuate when there is danger of fire, unstable position, hazardous spill, or it is in the path of a hazard (e.g., on railroad tracks). Choose the safest exit, lead students to a safe place at least 100 feet off the road in the direction of oncoming traffic, and account for all students.

In what direction and how far should evacuated school bus passengers be moved from the bus?

Move and keep students at least 100 feet off the road (or further if hazmat is involved), generally upwind and toward oncoming traffic, away from the bus and any hazard.

What does ABS (antilock braking system) do for a vehicle during hard braking?

ABS prevents the wheels from locking up during hard braking, allowing the driver to maintain steering control and avoid skids; it does not necessarily shorten stopping distance.

How do you tell if a tractor, trailer, or converter dolly is equipped with ABS?

Check for a yellow ABS malfunction lamp on the dashboard (tractor) or on the left side of trailers/dollies (front or rear corner), and look for the ECU and wheel-speed sensor wires near the brakes; trailers built after March 1, 1998 must have ABS.

How should you brake with ABS in an emergency stop?

Brake as you normally would — apply firm, continuous pressure (press the brake, hold it, keep your heel on the floor) and steer; with ABS you can press fully without fear of locking the wheels, but do not pump the brakes.

If only the trailer (or only the dolly) has ABS but not the tractor, what is the benefit?

You will likely have more stability and less chance of jackknifing on that unit; if the tractor has ABS but the trailer does not, you keep steering control. Any ABS-equipped wheel improves control, so use normal firm braking.

What is rearward amplification and why is it dangerous with doubles and triples?

Rearward amplification ('crack-the-whip' effect) is the increasing side-to-side movement transmitted to the rear trailers when the front unit turns; the last trailer can experience several times the lateral acceleration of the tractor, making it likely to tip over.

Roughly how much greater is the crack-the-whip effect on the rear trailer of triples compared to the tractor's movement?

The rear trailer of a triple can have a 'crack-the-whip' (rearward amplification) effect up to several times — around 2 to 3.5 times — the lateral acceleration of the tractor, greatly increasing rollover risk.

How should you steer and brake to reduce rollover risk when pulling doubles and triples?

Steer gently and smoothly (avoid quick lane changes or abrupt steering), slow down well before curves/ramps, and brake before a turn — sudden movements are amplified to the rear trailers and can cause the last trailer to roll over.

At what speed advantage should you take exit/entrance ramps when pulling multiple trailers?

Slow to well below the posted ramp speed (the posted speed is often too fast for doubles/triples); the crack-the-whip effect means the rear trailer can roll over at a speed that feels safe in the cab.

What is a converter dolly (converter gear) used for in doubles and triples?

A converter dolly is a coupling device with one or two axles, a fifth wheel, and a drawbar that connects to the rear trailer's kingpin; it converts a semitrailer into a full trailer so it can be towed behind another trailer.

What is a pintle hook and where is it found on a combination of doubles/triples?

A pintle hook is the coupling device mounted at the rear of the lead (front) trailer; the converter dolly's drawbar eye locks into the pintle hook to connect the dolly (and the trailer behind it) to the trailer ahead.

When inspecting a converter dolly, what specific items must you check?

Check the dolly's tires, wheels, lights/reflectors, and air lines; the fifth wheel for proper mounting and lubrication; the pintle eye and drawbar for cracks/damage; the safety chains; and that the dolly's tow bar latch is locked.

What is the correct procedure to couple a converter dolly to the rear of the first trailer?

Release the dolly brakes (or chock wheels), line up the dolly's pintle eye with the first trailer's pintle hook, secure the dolly to the trailer by closing and latching the pintle hook, and connect the safety chains.

How should a converter dolly be positioned before backing the second trailer over it?

Move the dolly to a position directly in front of the rear trailer, in line with the kingpin, with the fifth wheel jaws open and the fifth wheel tilted down (back) toward the trailer's kingpin so the trailer can settle onto it.

After connecting the dolly to the second trailer, how do you confirm the coupling is secure?

Make sure the trailer kingpin is locked in the fifth wheel (check that the jaws closed around the kingpin and the locking lever is in place), there is no space between the upper and lower fifth wheel, and then connect the air/electrical lines and supply air to the trailer.

Why must you supply air to the second trailer's brake system before pushing the dolly under it?

You should NOT supply air until the dolly is coupled to the rear trailer — but once coupled you charge the trailer air tank so the trailer brakes release; never push a dolly under a trailer with its brakes still charged/released and unsecured, as it can roll.

What is the correct order for uncoupling the rear trailer of a set of doubles?

Park on level ground in a straight line, set the rear trailer's parking brake (lower its landing gear/dolly support), disconnect the air and electrical lines, unlock the fifth wheel between the dolly and rear trailer, then pull the dolly out from under the trailer.

What should you check about the air lines (glad hands) when coupling multiple trailers?

Make sure the emergency (red) and service (blue) air lines are connected to the correct couplers (glad hands), are not crossed, and that the air lines and electrical cord are not pinched, dragging, or rubbing against moving parts.

How do you do a quick air-line/brake check after coupling doubles or triples?

After charging the system, check that air reaches the last trailer by opening the emergency line valve at the rear of the last trailer (you should hear air escape) or by applying the brakes and checking each trailer; this confirms all trailers' brakes are connected and working.

Why are doubles and triples more likely to roll over than a single trailer?

Because of rearward amplification (crack-the-whip), the higher center of gravity, more coupling points and play, and the fact that the rear trailers swing wider and experience amplified lateral forces, the rear trailers tip much more easily.

What is the recommended way to manage following distance and lane changes with doubles/triples on the highway?

Allow extra following distance and more space for lane changes because the units are long; change lanes gradually and avoid sudden maneuvers since any abrupt steering is amplified to the rear trailers and can cause loss of control or rollover.

What should you verify about the fifth wheel and kingpin when inspecting coupling of multiple trailers?

Verify the fifth wheel is properly greased, the locking jaws are fully closed around the kingpin, the release lever/handle is in the locked position, there is no gap between the trailer and fifth wheel, and the mounting bolts/brackets are secure with no cracks.

What special check applies to the landing gear (dolly legs) before moving a coupled set of trailers?

Make sure each trailer's landing gear is fully raised, the crank handle is secured, and the landing gear is not damaged, so it does not drag or catch when the rig moves.

When putting a combination of doubles/triples together, in what order should the trailers be placed by weight?

Place the most heavily loaded trailer first (directly behind the tractor) and the lightest trailer last; this lowers rollover risk because lighter rear trailers are even more prone to the amplified crack-the-whip rollover.