Iowa CDL General Knowledge Test study plan

Perform a complete pre-trip inspection in the correct order (engine off, engine on, air brake checks, walk-around) three times without prompts, naming each part and what a defect looks like

List the seven-step general inspection sequence from memory and write one sentence on why each step exists

Demonstrate straight-line backing, 90-degree alley docking, and offset backing in a lot or simulator, logging three attempts per maneuver

Define the three-point stance and the pivot-point technique for right turns, and write down five common turning errors that fail a road test

Read the Iowa CDL manual chapters on vehicle inspection and basic control, and mark every item you could not explain aloud

Explain how air pressure builds and is governed (compressor, governor cut-in/cut-out, reservoirs) and state typical cut-out and cut-in pressures

Describe the low-air warning threshold, the spring-brake pop-out pressure, and the correct action for each, then recite them without notes

Trace the path of air from compressor to brake chamber and identify what each valve does

Perform and document the three air-brake tests (leak-down with engine off and brakes released, leak-down with brakes applied, low-pressure warning) on a real or simulated system

Write out the procedure for a stalled engine with low air, and explain why you must not rely on the parking brake release

Identify each coupling component (fifth wheel, kingpin, locking jaws, safety latch, air lines, electrical cord, glad hands) and state the inspection point for each

Recite the coupling and uncoupling sequences in order, including the tug test and the visual low-gear pull

Explain trailer air supply and trailer protection valves and what happens when trailer pressure drops

Describe off-tracking, rearward amplification, and the correct swing path for a 53-foot trailer in a tight right turn

Diagnose five combination-vehicle faults (unlocked jaws, crossed air lines, missing safety latch, chafed cord, improper slider position) and state the symptom each produces

Shift a manual transmission through the full range (low through high) without grinding, logging ten clean upshifts and ten clean downshifts

Explain progressive shifting, rpm matching, and the reason for downshifting before a downgrade rather than during it

State the four factors that determine safe following distance and calculate following distance in seconds at 35, 55, and 65 mph

Describe stopping distance components (perception, reaction, brake lag, braking) and compute total distance at 55 mph on dry pavement

List the speed adjustments required for rain, curves, downgrades, and heavy traffic, and justify each with a stopping-distance number

List the top causes of truck crashes and match each to a specific defensive-driving countermeasure

Describe the hazard-perception process: scan ahead 12-15 seconds, check mirrors every 5-8 seconds, and identify escape routes

Identify ten roadside hazards (work zones, parked vehicles, pedestrians, animals, bridge heights, low wires) and state the response for each

Explain railroad crossing rules, including the stop requirements for buses and hazmat vehicles and the clearance rule

Walk through the correct response to a tire blowout, a brake failure, and a hydroplaning loss of traction, in order of actions

Explain weight limits, axle weights, gross vehicle weight, and bridge formula basics, and calculate whether a given load configuration is legal

Describe cargo securement requirements: tie-down count, working load limit, aggregate WLL, and inspection intervals

List the nine hazard classes and state the placarding threshold rule for each class you can confirm

Describe the shipping paper requirements, emergency response information, and the correct action after a hazmat release

Explain the rules for parking a hazmat vehicle, attending a loaded vehicle, and routing around tunnels and populated areas

Identify the four types of distraction (visual, manual, cognitive, auditory) and give a truck-specific example of each

State the phone and texting rules that apply to commercial drivers and explain the consequences of a violation on your record

Describe night-driving adjustments: speed, following distance, headlight use, glare recovery, and fatigue signs

Explain the correct response to fog, heavy rain, snow, ice, high wind, and extreme heat, including when to stop rather than continue

Describe winter chain-up decisions and the effect of cold on air brake performance and tire pressure

Take three full-length practice tests under timed conditions and score 90% or higher on each

Review every missed question and write the correct rule in your own words

Re-run the pre-trip inspection and air-brake tests cold, without notes, to confirm retention

Recite the top 20 facts you are least confident about until each is fluent

Simulate the test-day routine: documents ready, inspection sequence rehearsed, and a final 30-minute review of weak areas