Iowa (IA) CDL manual 2026
Reading the manual is not the same as passing the test on it. Practice it instead: every chapter below has real test questions you can answer right here, plus what Iowa does its own way.
Practice the manual, chapter by chapter
State manuals are built on the same national model, chapter for chapter. One thing to know from each chapter, then real questions from it to answer — tap an option to check yourself.
- 1
Introduction
Everyone
You must notify your employer within two business days if your license is suspended, revoked, or canceled, or if you are disqualified from driving.
This chapter has 26 more questions. Practice them in the app and see your pass chance.Your personal vehicle license is revoked for an alcohol violation. How long do you lose your CDL?
Alcohol, controlled substance, or felony violations in your own car cost you the CDL for a year. A second such violation, in either vehicle, is a lifetime loss.
Manual section 1.3.7
What is the minimum disqualification for a first violation of an out-of-service order?
Ignoring an out-of-service order costs at least 90 days on the first occasion, which is longer than two serious traffic violations combined.
Manual section 1.3.4
- 2
Driving Safely
Everyone
On rainy days, pedestrians may not see you because of hats or umbrellas; they may be hurrying to get out of the rain and may not pay attention to the traffic.
This chapter has 290 more questions. Practice them in the app and see your pass chance.You are the first driver to stop at a crash scene on a busy highway. After parking your vehicle safely, what should you do first?
The first duty at a crash scene is preventing a second collision, so the area must be protected with warning devices before anything else is attempted.
Manual section 2.20
What is the final action of the engine compartment step?
An unsecured hood or cab can come open at speed, which is why the step ends by closing and latching whatever was opened.
Manual section 2.1.5
- 3
Transporting Cargo Safely
Everyone
On flat bed vehicles, weight loaded so there is a high center of gravity creates a greater chance that the load will shift to the side or fall off.
This chapter has 26 more questions. Practice them in the app and see your pass chance.What happens when there is too little weight on the driving axles?
The drive wheels need weight on them to grip. Without it they spin, and in bad weather the truck may not be able to keep moving at all.
Manual section 3.2.4
Which of these is named as proper tie-down equipment?
Tie-downs must be of the proper type and strength, and they must be attached to the vehicle correctly using hooks, bolts, rails, or rings.
Manual section 3.3.2
- 4
Transporting Passengers
P endorsement (bus)
Mention rules about smoking, drinking or use of electronic devices at the start of the trip; explaining the rules at the start helps avoid trouble later on.
This chapter has 98 more questions. Practice them in the app and see your pass chance.You have finished loading at a curbside stop and are ready to rejoin traffic in your transit bus. What should you do first?
Before leaving a stop, the driver must check the mirrors to make sure the path is clear of vehicles, bicycles, and people walking near the bus.
Manual section 4.3
You are driving a bus toward a railroad crossing where a stop is required. Within what distance range before the nearest rail must you stop?
Buses must stop between 15 and 50 feet before the nearest rail at railroad crossings where a stop is required. From there the driver looks and listens in both directions for a train.
Manual section 4.3
- 5
Air Brakes
Any vehicle with air brakes
Wedge brakes may have a single brake chamber, or two brake chambers pushing wedges in at both ends of the brake shoes.
This chapter has 148 more questions. Practice them in the app and see your pass chance.How is the cab control for a front brake limiting valve normally marked?
The two positions are labeled normal and slippery, reflecting the mistaken belief that cutting front brake pressure helped on poor surfaces.
Manual section 5.1.13
How long a crack in a brake drum or disc is acceptable during inspection?
The limit is set against the friction area itself: nothing longer than half its width. A crack past that point can let the drum come apart under braking heat.
Manual section 5.3.2
- 6
Combination Vehicles
Class A
Never use the trailer hand valve while driving; danger of trailer skid or jackknife.
This chapter has 118 more questions. Practice them in the app and see your pass chance.What rearward amplification figure does the manual give for triples?
Triples come in at 3.5, meaning the last trailer can be rolled about three and a half times as easily as a five-axle tractor in the same quick maneuver.
Manual section 6.1.2
What happens when you push in the trailer air supply knob before starting a trip?
Pushing the knob in charges the trailer's air system through the emergency line, which releases the trailer's emergency brakes so the rig can move.
Manual section 6.2.3
- 7
Doubles and Triples
T endorsement
Charge the air system to normal pressure before checking air flow to the rear trailers.
This chapter has 98 more questions. Practice them in the app and see your pass chance.When hooking air lines between the first trailer and the converter dolly, how do you avoid crossing them?
Service and emergency lines are color coded, commonly blue for service and red for emergency, so matching like to like prevents crossed lines.
Manual section 7.2
What must you verify about the light cords when inspecting a set of doubles or triples?
A cord that has worked loose kills the lights on everything behind it, leaving the rear of a very long rig invisible at night.
Manual section 7.3.1
- 8
Tank Vehicles
N endorsement
Check the tank's body or shell for dents or leaks.
This chapter has 62 more questions. Practice them in the app and see your pass chance.During a pre-trip inspection of a cargo tank, what is the most important thing to check the tank body, piping, and valves for?
The single most important tank inspection item is checking for leaks. It is illegal and dangerous to transport cargo in a leaking tank, and the driver can be cited and shut down for doing so.
Manual section 8.1
Compared with most other kinds of cargo, why does a load of liquid in a tank make a truck easier to roll over?
A cargo tank places the load well above the pavement, giving the vehicle a high center of gravity. The higher the weight rides, the less sideways force it takes to tip the vehicle over.
Manual section 8.2
- 9
Hazardous Materials
H endorsement
Attending the vehicle means being on it and awake outside the sleeper berth, or within 100 feet with a clear and unobstructed view of it.
This chapter has 234 more questions. Practice them in the app and see your pass chance.What equipment must a driver hauling chlorine in cargo tanks carry?
Two specific items are required: an approved gas mask in the vehicle, and an emergency kit for controlling leaks in the dome cover plate fittings.
Manual section 9.6.11
What is required of the surface a placard is mounted on?
A placard that blends into the panel behind it may not register at a distance, so the background has to contrast with it.
Manual section 9.3.10
- 10
School Buses
S endorsement
The rear of a school bus swings outward during turns, so drivers must check mirrors to keep the tail swing path clear.
This chapter has 98 more questions. Practice them in the app and see your pass chance.How far upwind should students be led if spilled hazardous materials are a risk?
A hazmat risk calls for at least 300 feet upwind, considerably farther than the 100 feet used for an ordinary roadside evacuation.
Manual section 10.3.2
About how far before a railroad crossing should a school bus driver activate the hazard lights?
Hazard lights go on roughly 200 feet out, which tells the traffic behind you that this bus is going to stop at the tracks.
Manual section 10.4.3
- 11
Pre-Trip Vehicle Inspection
Everyone (skills test)
Cracks, breaks, or holes in the cargo area can result in possible loss of cargo.
This chapter has 200 more questions. Practice them in the app and see your pass chance.At what speed is the service brake check performed?
You pull forward at about 5 mph and apply the foot brake to a complete stop, watching for any pull to one side.
Manual section 11.1.1
How many parts make up the air brake check, and what happens if you get one wrong?
The air brake check has four parts, and failing to explain and demonstrate all four correctly is an automatic failure of the Vehicle Inspection test.
Manual section 11.1.2
What’s different in Iowa
Most of every state manual is the same federal material. These are the parts that are not.
- Skills test: the modernized skills test.
- Checklist on the pre-trip: Yes. You may use a blank checklist as a memory aid during the vehicle inspection.
The official Iowa CDL manual
Published free by Iowa Department of Transportation, Motor Vehicle Division
On their site, search for “CDL manual” to download the latest edition.