CDL Doubles/Triples study plan

CDL Doubles/Triples · Give each week a clear focus.

8 weeks · About 6 hours per week

Week 1

Coupling and Uncoupling & Inspecting Doubles and Triples

Write out the full coupling sequence in order, naming each step from approach to pull test, without notes.
Identify the fifth wheel, kingpin, locking jaws, release handle, glad hands, and electrical cord on a labeled diagram and state each part's function.
Recite the pre-trip inspection items unique to a converter dolly, including the tow bar and safety devices.
Explain the three most common coupling failures (high hook, low hook, missed kingpin) and the damage each causes.
Demonstrate the tug test procedure and describe what a correct versus failed tug looks like.

Handwritten coupling checklist covering every step in correct order, self-scored 100% against the manual sequence.

Week 2

Sequence the uncoupling procedure correctly, including landing gear, air line disconnection order, and pull-away.
Build a written inspection checklist for the second and third trailers covering lights, brakes, tires, and safety devices.
Contrast the inspection differences between a two-trailer and a three-trailer configuration.
State why backing a coupled set is prohibited and what must be done instead.
Explain how to verify that trailer brakes and emergency lines are functioning before moving.

Timed 20-item self-quiz on coupling, uncoupling, and inspection; score at least 85% and log every missed item with a correction.

Week 3

Define off-tracking and explain how much the rear trailer cuts a corner in a right turn.
List the steps for a safe lane change with a long combination, including mirror checks and signal timing.
Explain three causes of rear-trailer sway and the correct recovery action.
Describe speed and space management for turns, curves, and downgrades with multiple trailers.
Identify the hazards of crosswinds and passing large vehicles when pulling doubles or triples.

10-question practice set on driving doubles/triples, scored at least 80%, with a one-paragraph written summary of sway correction.

Week 4

Explain how the dual air brake system divides service between the tractor and the trailers.
State the low-air-pressure warning threshold and the pressure at which spring brakes apply.
Perform the static leakage test steps and recall acceptable leak rates for tractor and trailer.
Describe how to test the trailer hand valve and the tractor protection valve.
Explain what happens to trailer brakes during a breakaway.

Milestone exam of 40 mixed questions spanning domains 2, 3, 4, and 5, scored at least 80%.

Week 5

Recite the full air brake inspection sequence for a double or triple combination, including the dolly.
State the function of the relay valve, tractor protection valve, and spring brakes in a multi-trailer set.
List at least three advantages and three disadvantages of pulling doubles or triples.
State the general rules and endorsement requirements that apply to pulling double and triple trailers.
Explain how weight distribution and axle placement affect handling of a multi-trailer combination.

One-page air brake inspection card written from memory, listing every step with the correct pressures and thresholds.

Week 6

Explain the crack-the-whip effect and describe how to prevent it.
Describe the correct procedure for adding or removing a third trailer, including the order of connection.
State the legal and safety limits on trailer length, kingpin-to-rear-axle distance, and total combination length.
Review domain 1 material and complete a 30-question mixed practice set.

30-question mixed practice set across domains 1 and 5, scored at least 85%, with a written correction log.

Week 7

Retake every previously missed question from weeks 1 through 6 and explain why each wrong answer was wrong.
Complete two full-length practice exams under timed conditions.
Drill flashcards on coupling order, inspection items, and air brake thresholds daily.
Rank your five weakest subtopics and build a two-day remediation list for each.

Two full-length timed practice exams, both scored at least 85%, plus a ranked list of remaining weak areas.

Week 8

Complete three consecutive full-length practice exams without reviewing notes between them.
Recite the coupling and uncoupling sequences and the air brake inspection card from memory one final time.
Review only flagged weak spots from week 7 and confirm each is resolved.
Simulate test-day conditions: quiet room, timer, no reference material.

Three consecutive practice exams scored at least 90%, with all previously flagged weak areas marked resolved.

Week 2: Can write the complete coupling and uncoupling sequences from memory and score at least 85% on the 20-item inspection quiz.

Week 4: Score at least 80% on the 40-question milestone exam covering the three heaviest domains plus air brakes.

Week 6: Score at least 85% on mixed practice and correctly state every air brake pressure threshold from memory.

Week 8: Three consecutive full-length practice exams at 90% or higher, with no unresolved weak areas.