Iowa CDL DMV Endorsement Double 1

The suspension system holds up a vehicle and its load while keeping the axles in place. Defects in this system are extremely dangerous.

Driving in reverse is always dangerous because you cannot see everything behind your vehicle. Whenever possible, use a helper to monitor your blind spots.

A skid caused by over-acceleration can be resolved simply by removing your foot from the accelerator. Skids of this nature happen most frequently on surfaces covered in snow or ice.

Gravity causes a vehicle's speed to increase when traveling on a downgrade. Adjust your speed before reaching a downgrade.

Driving at night is more dangerous than driving during the day because hazards become more difficult to see in the dark.

B:C fire extinguishers are designed to work on electrical fires and burning liquids. Don't pour water on an electrical fire.

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.

On a slippery road, you must adjust your driving speed to fit conditions. Because it will take longer for your vehicle to stop on a slippery road than on a dry road, you should increase your following distance when conditions are slippery. Avoid driving in a way that requires you to change speeds frequently.

Most drivers are the least alert at night, especially after midnight. Therefore, crashes due to fatigued driving are more likely at night than any other time of day.

To make a normal stop in a vehicle that is equipped with air brakes, you should simply press the brake pedal down.

When positioning trailers in a combination, the most heavily-loaded trailer should be the closest to the tractor. The lightest trailer should be positioned in the rear.

Before a trip, you should check each slack adjuster after parking, setting wheel chocks, and disengaging the parking brake. Pull the slack adjusters to make sure that they do not move more than about one inch from where the push rod is attached. If they move more than one inch, they may be out of adjustment and will need to be fixed.

An Anti-Lock Braking System (ABS) helps to provide additional control during hard braking, but does not necessarily shorten a vehicle's stopping distance.

Every combination vehicle has two air lines: the service line and the emergency line.

A vehicle's regular stopping distance increases on slippery surfaces because there is less available traction.

Before driving a vehicle with a dual air brake system, allow time for the air compressor to build up a minimum of 100 psi pressure in both the primary and secondary systems. Watch the air pressure gauges to monitor the pressure levels.

Always watch for hazards on the road ahead. Doing this will allow you time to react to hazards before meeting them.

The leading cause of injury and death in roadway work zones is excessive speed by passing drivers. Lower your speed when driving through a work zone.

Skids caused by acceleration frequently occur on slippery road surfaces. These skids can generally be resolved by the driver removing their foot from the accelerator.

Use your low beam headlights when traveling near other drivers at times when it is difficult to see, such as at dawn, at dusk, or in poor weather conditions. Using the high beam setting under certain conditions could make it difficult for other drivers to see.