Iowa Combination Vehicles CDL Practice Test
Practice with real IA Combination Vehicles exam questions and detailed explanations. Rated 4.8 stars by 1,000+ drivers.
Written by CDL holders and exam prep experts · Updated April 2026
Free Questions
10
Passing Score
80%
Time Limit
Typically 30 minutes; varies by testing location
Prerequisites
General Knowledge and Air Brakes tests must be completed first
What is the Combination Vehicles Test?
The Combination Vehicles test is required to obtain a Class A CDL, which allows you to drive truck-trailer combinations where the trailer weighs more than 10,000 pounds. This test covers the skills and knowledge needed to safely operate tractor-trailers and other combination vehicles.
Required for Class A CDL (tractor-trailers)
Topic Breakdown
Coupling and Uncoupling
~6 questions
- Pre-coupling inspection procedures
- Proper coupling techniques
- Safe uncoupling procedures
Vehicle Inspection
~5 questions
- Trailer inspection procedures
- Fifth wheel and kingpin checks
- Air line and electrical connections
Driving Techniques
~5 questions
- Backing with trailers
- Turning and cornering safely
- Managing trailer swing
Safety Considerations
~4 questions
- Rollover prevention
- Brake usage and stopping distance
- Weight distribution effects
Free Practice Questions
10 questionsQuestion 1 of 10
After you have coupled the trailer you should raise the landing gear by first using:
Browse Iowa Combination Vehicles Questions
- 1. After you have coupled the trailer you should raise the landing gear by first using:
- 2. You are driving a combination vehicle when the trailer breaks away, pulling apart both air lines. You expect the trailer brakes to come on and:
- 3. When driving behind another vehicle, under good conditions, you should allow at least one second between your vehicle and the vehicle ahead for each ____ feet of your vehicle length.
- 4. What is the most common cause of a tractor-trailer jackknife?
- 5. The combination of which two things will greatly reduce the likelihood of a rollover?
- 6. Off-tracking or cheating causes which of these to follow the wider path while making a turn?
- 7. What is the purpose of the trailer air supply control?
- 8. Which part of the kingpin should the locking jaw close around?
- 9. After you lock the kingpin into the fifth wheel, you should check the connection by:
- 10. Glad hands are usually connecting which of these?
Study Tips for Iowa
- 1Practice coupling and uncoupling procedures step-by-step
- 2Learn the fifth wheel inspection points thoroughly
- 3Study trailer backing techniques and reference points
- 4Understand weight distribution and bridge laws
- 5Review state combination vehicle regulations
Iowa CDL Information
Age Requirements
Intrastate: 18+ · Interstate: 21+
CDL Renewal
Every 5 years
ELDT Required
Yes — ELDT (Entry-Level Driver Training) from FMCSA-registered provider
Iowa DOT
Official CDL Portal →Career Opportunities
Frequently Asked Questions
You need to pass the Combination Vehicles test to obtain a Class A CDL, which allows you to drive truck-trailer combinations where the trailer weighs more than 10,000 pounds.
Combination Vehicles Study Resources
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