Iowa CDL — General Knowledge practice
Iowa CDL — General Knowledge: Parking & Stopping practice test
Legal and illegal parking, colored curbs, distances from hydrants and crossings, and how to park safely on hills.
Content reviewed against official driver handbooks · August 12, 2026
13 questions · pass with 10 correct. You get instant feedback and an explanation after every answer.
Study questions with answers
12 sample Parking & Stopping questions with the correct answer, a short explanation, and the official handbook reference. Read through them, then take the quiz above.
Show all 12 questions with answers
1. Your test vehicle's parking brake valve isn't designed to pop out. How do you show during the air brake check that the parking brakes applied?
Correct answer: Listen for air discharging from the system
If the valves aren't built to pop out, listen for the sound of air being released, which tells you the parking or emergency brakes have applied.
Source: Iowa Commercial Driver's License Manual — Section 11.1.2, Air Brake or Hydraulic Brake Check
2. During forward offset tracking, what does the examiner score besides encroachments?
Correct answer: Whether the right-most rear tire stays between the cone and the line
You're scored for encroachments and for forward tracking clearance, meaning the right rear tire must pass between the cone and the line.
Source: Iowa Commercial Driver's License Manual — Section 12.2.3, Exercise 3 – Forward Offset Tracking
3. You encroach on a boundary during a skills exercise. What will happen next?
Correct answer: The examiner stops you, and you must bring the vehicle back inside the boundaries
After an encroachment, the examiner halts you and you have to move the vehicle back inside the exercise boundaries. Each one counts as an error.
Source: Iowa Commercial Driver's License Manual — Section 12.1, Scoring
4. When is the straight-line backing exercise complete?
Correct answer: When your vehicle's front end has passed the final pair of cones at the alley's far end
Keep reversing in a straight line until the vehicle's front end is past the final cones at the far end, then set the brake, shift to neutral or park, and sound the horn.
Source: Iowa Commercial Driver's License Manual — Section 12.2.2, Exercise 2 – Straight Line Backing
5. How is the forward stop exercise scored on the basic control skills test?
Correct answer: Points are assessed when the vehicle's leading edge ends up outside the stop box
Pull forward through the alley and make a single stop so the vehicle's leading edge lands in the box at the end without passing it. You're penalized if it ends up outside the box.
Source: Iowa Commercial Driver's License Manual — Section 12.2.1, Exercise 1 – Forward Stop
6. On the backing exercises, how are pull-ups beyond the free ones treated?
Correct answer: They count as errors
Initial pull-ups aren't penalized, but an excessive number count as errors. The examiner explains the allowance when giving instructions.
Source: Iowa Commercial Driver's License Manual — Section 12.1, Scoring
7. Before holding the foot brake for the one-minute air leakage test, what must you release?
Correct answer: The parking brake, plus the tractor protection valve on a combination
Shut off the engine, turn the key to on or battery charge, release the parking brake (and the tractor protection valve on a combination), then fully apply the foot brake.
Source: Iowa Commercial Driver's License Manual — Preparing for Your Brake Check
8. During the air brake check, within what pressure range should the parking (emergency) brake valve pop out?
Correct answer: Between 20 and 45 psi
As you keep fanning off air, the parking or emergency brake valve should pop out somewhere from 20 to 45 psi, never below 20 or above 45, unless the manufacturer specifies otherwise.
Source: Iowa Commercial Driver's License Manual — Preparing for Your Brake Check
9. Must the basic control skills exercises always be given on a separate off-road course?
Correct answer: No, they may be given off-road or on the street during the road test
The exercises can be given on an off-road course or out on the street as part of the road test.
Source: Iowa Commercial Driver's License Manual — Section 12, Basic Control Skills Test
10. Your vehicle has primary and secondary air systems. What should you explain during the air brake check about the parking brake valves?
Correct answer: A backup system exists, so the valves won't pop out from a loss in only one system
With a primary and secondary system, explain that there is a backup and that losing pressure in just one system won't make the valves pop out.
Source: Iowa Commercial Driver's License Manual — Section 11.1.2, Air Brake or Hydraulic Brake Check
11. If the examiner permits it, what may you ask for before starting the basic control exercises?
Correct answer: A walk-through of the exercise area
Where permitted, you can request that the examiner guide you through the exercise area on foot. Ask questions whenever the instructions aren't clear.
Source: Iowa Commercial Driver's License Manual — Section 12.1, Scoring
12. On a combination vehicle with an air-braked trailer, when should the tractor protection valve and the trailer parking brake valve close during the brake check?
Correct answer: At the same time as, or before, the tractor's parking brake valve
When the trailer has air brakes, its parking brake valve and the tractor protection valve should close together with, or ahead of, the power unit's valve.
Source: Iowa Commercial Driver's License Manual — Section 11.1.2, Air Brake or Hydraulic Brake Check
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Every Iowa question is written from the official Iowa driver handbook and checked against its current edition. DMV Test Free is a free, independent study resource — not affiliated with any DMV or government agency. About DMV Test Free