Iowa CDL DMV Knowledge Test Class A 1

It is a driver's responsibility to make sure their vehicle is not overloaded. They must be aware of legal weight limits and the maximum weight that their vehicle is rated to carry, including the weight capacity rating of the suspension system.

Most heavy vehicles with unsynchronized manual transmissions require double clutching to change gears.

Because you can't see everything behind you, backing is always dangerous and should be avoided whenever possible. Choose parking spaces from which you can pull forward when you leave.

If you are not sure which kind of extinguisher should be used on a fire in your vehicle, particularly a hazardous materials fire, you should wait for the firefighters to arrive and allow them to extinguish it.

When performing a static leakage test on a single vehicle with air brakes, the leakage rate should be no more than 2 psi in a minute. If the air leaks from the air brake system at a quicker rate, the vehicle should not be driven because something likely needs to be repaired.

A first conviction of causing a fatality through negligent operation of a CMV will result in the loss of your CDL for at least one year.

An Individual Vehicle Distance Record (IVDR) must include information about the distance traveled by a vehicle and the amount of fuel purchased. The required distance information includes the dates of a trip and the total distance traveled by the vehicle.

Compressed air in an air brake system usually contains a certain amount of water and compressor oil. The water and oil can damage the brakes if left to accumulate in the system. Manually operated air tank drains must be opened daily to remove this build-up.

Strong winds can make it difficult for a driver to maintain control of their vehicle. Usually, this is especially true for drivers of lighter CMVs.

You should always slow to a safe speed before entering a curve. Slowing while within the curve could cause a skid.

During a trip, you should regularly make checks to ensure that your vehicle is operating properly. Check the instrument panel and gauges; look at your mirrors; and examine the tires, cargo, and lights. Use all of your senses and be alert for anything that could be an early indication of trouble.

Dry bulk tanks require special care to be driven, both because they have high centers of gravity and because the weight of the load can shift in transit.

Driving in fog is always dangerous and should be avoided entirely if at all possible. If you must drive in fog, be sure to turn on your low beam headlights and fog lights, even during the daytime.

When making mirror checks, you should look at the mirrors fairly quickly. If you spend too much time looking in a mirror, you may travel a substantial distance down the road without seeing what is coming up ahead.

Texting while driving is a dangerous distraction and is prohibited at all times when operating a CMV.

You will not be able to brake or steer your vehicle without adequate traction. Ensure that your tires are in proper working condition before beginning a trip.

If your brakes fail on a downgrade, you will have to look outside your vehicle for a way to stop. Using an escape ramp is the safest way to stop your vehicle.

If you see a distracted driver, give them plenty of space and maintain a safe following distance.

If you are not sure which method to use when putting out a fire, do not attempt to extinguish the fire on your own. Instead, wait for firefighters to arrive and let them handle it. This is especially true if you are experiencing a hazardous materials fire.

If you must stop on the side of the road, you must place the appropriate emergency warning devices within 10 minutes of stopping.

If confronted by an aggressive driver, don't let yourself be provoked by their actions or angry gestures. Do not risk provoking the other driver by making eye contact. Get out of their way if you can do so safely.

If you are asked to complete an offset back/left parking maneuver, you should first pull straight forward, then back up to the left. Your vehicle must be parked completely within the boundaries of the parking space.

In a vehicle with dual parking control valves, there is a separate air tank that can be used to temporarily release the spring brakes if they have been activated due to low air pressure. Pushing in the proper control will release the spring brakes for a short period of time, allowing the driver to move the vehicle in an emergency.

It is best not to avoid driving in fog. However, if you must drive under foggy conditions, be sure to decrease your speed.

The securement of cargo must be checked before beginning a trip, within the first 50 miles of a trip, and then again every three hours or 150 miles thereafter.

To avoid engaging in aggressive driving behavior, it is helpful to give other drivers the benefit of the doubt. Assume that they have valid reasons for what they are doing and don't take their actions personally.

When backing with a trailer, begin by turning the steering wheel in the direction opposite of the turn. Once the trailer starts to turn, reverse the direction of the steering wheel to follow the trailer.

It is important to communicate your intentions to others on the road. Make sure to signal before turning or changing lanes, even if no other vehicles are nearby.

In an air brake system, the air tanks must be periodically drained to remove accumulations of water and compressor oil. If water is not removed, it could freeze in cold weather and cause brake failure.

On flatbed trailers and trailers without sides, cargo must be tied down. There should be at least one tie-down for every 10 feet of cargo. Regardless of the size of the cargo, at least two tie-downs must be used.

Be sure to activate the appropriate turn signal well in advance of a turn or lane change. Signal continuously throughout the turn and make sure to cancel the signal after the turn is completed, if your vehicle doesn't have self-canceling signals.

Radial and bias-ply tires should not be used together. All wheels on a vehicle should be the same style and equally-sized.

You should not rely solely upon the presence of warning signals, gates, or flaggers to alert you to the approach of a train. Be especially alert to approaching trains at crossings that are not controlled by gates or signals. At any railroad crossing, you should operate under the assumption that a train is coming.

An air brake system has a safety relief valve, which releases air from the tanks if the pressure gets too high. If the valve must operate, something in the system is wrong and should be addressed by a mechanic.

During the vehicle inspection test, you will be asked to do a complete inspection of your vehicle. You will need to explain what you are inspecting and why.