Maryland CDL DMV Knowledge Test Class A 2

If you must drive in reverse, you should first walk around the vehicle to check for hazards in your path of travel. Make frequent use of the mirrors on both sides of your vehicle while backing. Always back up as slowly as possible.

Always decrease your speed when traveling through a construction area. Slow down even further if there are workers on or near the roadway.

If your drive wheels begin to spin while accelerating on a surface with poor traction, you should remove your foot from the accelerator.

Always change lanes slowly and smoothly. If you did not see drivers who are already using the lane you wish to occupy, this will give them a chance to get out of your way or honk their horns to alert you. Always signal when changing lanes.

When checking the tires as part of a pre-trip inspection, make sure the tires have sufficient tread. There should be at least 4/32 of an inch of tread in every major groove of the front tires, and at least 2/32 of an inch of tread depth on the other tires. Tire sizes should not be mismatched.

Always apply the parking brake when leaving your vehicle unattended.

All commercial motor vehicles are required to be equipped with the proper emergency equipment. This may include spare electrical fuses; three red reflective triangles, six fuses, or three liquid burning flares; and at least one properly charged and rated fire extinguisher.

Most heavy-duty vehicles use dual air brake systems, in which there are two separate braking systems operated by a single set of controls. Each system operates the brakes on different axles.

When inspecting a vehicle equipped with power steering, you should inspect the hoses, pumps, and fluid levels. Specifically check the hoses for leaks.

Strategies to avoid becoming an aggressive driver include having realistic expectations about your travel time and the possibility of delays; driving an appropriate speed and keeping a reasonable following distance; avoiding gesturing at other drivers; and keeping your hands on the wheel.

The total stopping distance for vehicles equipped with air brakes is made up of four factors: perception distance, reaction distance, brake lag distance, and braking distance. When braking at a speed of 55 mph while driving on dry pavement, the brake lag can add around 32 feet to a vehicle's total stopping distance.

You should stay in the right lane of a multilane road if your vehicle is being slowed down by a heavy load. Allow other vehicles to pass your truck using the left lane.

Skids happen when tires' traction with the road surface decreases. This can be caused by over-braking, over-accelerating, over-steering, and driving too fast.

A pre-trip vehicle inspection should be done in the same way every time. Consistency will help a driver learn all of the proper steps and decrease the possibility of the driver forgetting to inspect something.

Before starting down a hill, be sure to switch into a low gear. Gravity will increase your vehicle's speed as you travel downhill.

If you are turning to avoid a hazard, do not apply the brakes while you are turning. This could easily lock the wheels and create a skid.

If you think the road surface may be becoming icy, you can check for ice on your vehicle by opening the window and feeling the front of the side mirror, mirror support, or antenna. If ice has formed on any of these items, the road is likely becoming icy as well.

At dawn or dusk, and in snowy or rainy conditions, you should turn on your headlights to make it easier for other road users to see your vehicle.

Pressing and releasing the brake pedal unnecessarily can let air out faster than the compressor can replace it, reducing the available air pressure. If the air pressure in an air brake system gets too low, the brakes will no longer work.

In work zones, you should drive at the posted speed limits. Reduce your speed even further when workers are on or near the road.

When driving under foggy conditions, lights cannot be taken as a reliable indication of where the road is. The lights may be coming from a vehicle that has pulled off the road.

The air that enters air storage tanks in an air brake system usually contains a certain amount of water and compressor oil. Because accumulations of these materials can damage the braking system, tanks are equipped with drains to allow their removal.

Some air brake systems contain an alcohol evaporator. An evaporator introduces alcohol into the system to help inhibit the formation of ice in cold weather.

When making a left turn, you should wait until you reach the center of the intersection before actually beginning to turn. Due to off-tracking, the left side of your vehicle could hit another driver if you begin turning too early.

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.

You should make frequent mirror checks to monitor the traffic around you. This should help you notice if surrounding vehicles begin to move into your blind spots.

Posted speed limits on exit and entrance ramps often show speeds that are safe to be driven by cars. However, these speed limits may be too fast for large or heavily-loaded vehicles and CMV drivers will likely need to slow down to a speed below the posted limit.

There are two indicators that determine when you need to shift into a higher gear. One indicator is the engine speed (rpm). You should read your vehicle's manual to learn its rpm range and shift up when you reach the top of that range. The other indicator is road speed (mph). You should learn which speeds each gear can accommodate, then keep an eye on the speedometer and shift up as needed.

Air brakes consists of three separate braking systems: the service brake system, the parking brake system, and the emergency brake system. The service brake system applies and releases the brakes when you use the brake pedal while driving normally.

If the brakes pull to one side or the other when used, it is an indication of brake trouble.

You may be able to tell that another driver is distracted if you can see them drifting within a lane or across lane dividers; traveling at inconsistent speeds; being preoccupied with a cell phone, a map, food, or other items; or engaging in conversation with passengers.

A visual low pressure warning signal should activate before air pressure drops to a level between 55 and 75 psi. This signal could be a light, a buzzer, or a wig wag.

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

It is essential that exhaust system parts are not leaking or otherwise broken. A faulty exhaust system can let poisonous fumes into the cab or sleeper berth.

If you observe a crash involving an aggressive driver, you should stop a safe distance from the crash scene, wait for police to arrive, and inform them of the aggressive behavior you witnessed.