## Review Questions - Click On The Picture To Begin...

- Perception Distance, Reaction Distance, and Braking Distance
- Reaction Distance, Skid Distance, and Friction Distance
- Braking Distance, Forward Momentum Distance, and Friction Resistance
- Perception Distance, Braking Distance, Pressure Distance

#### Quote From The CDL Manual:

Three things add up to total stopping distance:

Perception Distance

+ Reaction Distance

+ Braking Distance

---------------------------------

= Total Stopping Distance

#### TruckingTruth's Advice:

This formula will almost definitely show up on your written exam so it's extremely important to not only memorize the formula, but memorize what each definition means:

- Perception distance is the distance your vehicle travels from the time your eyes see a hazard until your brain recognizes it. The perception time for an alert driver is about 3/4 second. At 55 mph, you travel 60 feet in 3/4 second.
- Reaction distance is the distance traveled from the time your brain tells your foot to move from the accelerator until your foot is actually pushing the brake pedal. The average driver has a reaction time of 3/4 second. This accounts for an additional 60 feet traveled at 55 mph.
- Braking Distance is the distance it takes to stop once the brakes are applied. At 55 mph on dry pavement with good brakes, it can take a heavy vehicle about 170 feet and about 4 1/2 seconds to stop.
- Total stopping distance - At 55 mph it will take about 6 seconds to stop and your vehicle will travel the distance of a football field (60 + 60 + 170 = 290 feet).

- 250 feet
- 275 feet
- 320 feet
- 419 feet

#### Quote From The CDL Manual:

At 55 mph, your vehicle will travel a minimum of 419 feet.

#### TruckingTruth's Advice:

Make sure you have the Total Stopping Distance Formula memorized and each term of the formula memorized as well.

Perception Distance (60 feet)

+ Reaction Distance (60 feet)

+ Braking Distance (170 feet)

-----------------------------

= Total Stopping Distance (290 feet, the length of a football field)

- 142 feet
- 100 feet
- 40 feet
- 70 feet

#### Quote From The CDL Manual:

**Perception distance** is The distance your vehicle travels, in ideal conditions; from the time your eyes see a hazard until your brain recognizes it. Keep in mind certain mental and physical conditions can affect your perception distance. It can be affected greatly depending on visibility and the hazard itself. The average perception time for an alert driver is 1¾ seconds. At 55 mph this accounts for 142 feet traveled.

#### TruckingTruth's Advice:

Perception time and distance should be memorized as it will very likely show up on your written exam.

- All of these answers describe Reaction Distance
- The distance your vehicle travels from the time your eyes see a hazard until your brain recognizes it
- The distance it takes to stop once the brakes are applied
- The distance traveled from the time your brain tells your foot to move from the accelerator until your foot is actually pushing the brake pedal

#### Quote From The CDL Manual:

Reaction distance is the distance you will continue to travel, in ideal conditions; before you physically hit the brakes, in response to a hazard seen ahead. The average driver has a reaction time of ¾ second to 1 second. At 55 mph this accounts for 61 feet traveled.

#### TruckingTruth's Advice:

It is very important to memorize the definition of Reaction Distance as well as memorizing Reaction Time and the distance traveled at 55mph. Nearly all written exams have questions about either Perception Distance, Reaction Distance, Braking Distance, or Total Stopping Distance. Make sure you know the definitions and distances for each.

- Braking distance
- Reaction distance
- All of these add up to total stopping distance
- Perception distance

#### Quote From The CDL Manual:

Three things add up to total stopping distance:

Perception Distance

+ Reaction Distance

+ Braking Distance

---------------------------

= Total Stopping Distance

#### TruckingTruth's Advice:

Be sure to memorize this formula as well as memorizing the definitions for:

Perception Distance Reaction Distance Braking Distance Total Stopping Distance

- 75 feet
- 80 feet
- 61 feet
- 100 feet

#### Quote From The CDL Manual:

The average driver has a reaction time of 3/4 second. This accounts for an additional 60 feet traveled at 55 mph.

#### TruckingTruth's Advice:

Be sure you memorize the definition or reaction time, including the distance traveled at 55mph.

- The distance it takes to stop once the brakes are applied
- The distance traveled from the time your brain tells your foot to move from the accelerator until your foot is actually pushing the brake pedal
- None of these accurately describe Braking Distance
- The distance your vehicle travels from the time your eyes see a hazard until your brain recognizes it

#### Quote From The CDL Manual:

Braking Distance is the distance it takes to stop once the brakes are applied. At 55 mph on dry pavement with good brakes, it can take a heavy vehicle about 170 feet and about 4 1/2 seconds to stop

#### TruckingTruth's Advice:

Make sure you memorize the definition of braking distance as this will likely show up on your written exam. You should also memorize braking time as well.

- Empty and light trucks always stop quicker than a heavy and loaded truck
- Empty and light trucks will only stop faster on slick or wet roadway conditions
- Empty and light trucks will only stop faster on dry roadway conditions
- Empty and light trucks never stop as quickly as a loaded truck

#### Quote From The CDL Manual:

The heavier the vehicle, the more work the brakes must do to stop it and the more heat they absorb. But the brakes, tires, springs and shock absorbers on heavy vehicles are designed to work best when the vehicle is fully loaded. Empty trucks require greater stopping distances, because an empty vehicle has less traction. It can bounce and lock up its wheels, giving much poorer braking. (This is not usually the case with buses.)

#### TruckingTruth's Advice:

A question regarding stopping distance with a loaded or empty truck will likely be included on your written exam. Be sure you understand why an empty truck takes longer to stop.

- About 200 feet
- About 165 feet
- About 216 feet
- About 150 feet

#### Quote From The CDL Manual:

At 55 mph on dry pavement with good brakes, it can take a heavy vehicle about 216 feet to stop.

#### TruckingTruth's Advice:

Make sure you memorize the definition of Braking Distance as well as the time and distance it takes for a vehicle to stop once the brakes are fully applied.

- The brakes, tires, springs and shock absorbers on heavy vehicles are designed to work best when the vehicle is fully loaded.
- Empty trucks require greater stopping distances, because an empty vehicle has less traction
- A heavily loaded truck will take longer to stop than an empty truck.
- The heavier the vehicle, the more work the brakes must do to stop it and the more heat they absorb

#### Quote From The CDL Manual:

The heavier the vehicle, the more work the brakes must do to stop it and the more heat they absorb. But the brakes, tires, springs and shock absorbers on heavy vehicles are designed to work best when the vehicle is fully loaded. Empty trucks require greater stopping distances, because an empty vehicle has less traction. It can bounce and lock up its wheels, giving much poorer braking. (This is not usually the case with buses.)

#### TruckingTruth's Advice:

This type of question is frequently asked on written exams. Understand that truck braking systems are designed for when the truck is fully loaded. An empty or very light truck will actually take longer to stop than a fully loaded and heavy truck.

- About five times as much distance is needed to stop
- About one and a half times as much distance is needed to stop
- About four times as much distance is needed to stop
- About twice as much distance is needed to stop

#### Quote From The CDL Manual:

Whenever you double your speed, it takes about four times as much distance to stop, and your vehicle will have four times the destructive power if it crashes. High speeds increase stopping distances greatly. By slowing down a little, you can gain a lot in reduced braking distance.

- Perception Distance
- Reaction Distance
- Braking Distance
- Total Stopping Distance

#### Quote From The CDL Manual:

Braking Distance is the distance it takes to stop once the brakes are applied. At 55 mph on dry pavement with good brakes, it can take a heavy vehicle about 216 feet to stop.

#### TruckingTruth's Advice:

Remember, braking distance is only one of three parts of the total stopping distance formula. Be sure to memorize the entire stopping distance formula:

Perception Distance

+ Reaction Distance

+ Braking Distance

---------------------

= Total Stopping Distance

- 1-3/4 second
- 1/8 second
- 1/2 second
- 1 second

#### Quote From The CDL Manual:

The average perception time for an alert driver is 1¾ seconds. At 55 mph this accounts for 142 feet traveled.

#### TruckingTruth's Advice:

Perception time and distance must be memorized.

- Reaction Distance
- Perception Distance
- Braking Distance
- Total Stopping Distance

#### Quote From The CDL Manual:

Perception distance is the distance your vehicle travels from the time your eyes see a hazard until your brain recognizes it. The perception time for an alert driver is about 3/4 second. At 55 mph, you travel 60 feet in 3/4 second.

#### TruckingTruth's Advice:

Take a moment to memorize the definition for Perception Distance. This will very likely show up on your written exam.

- None of these are correct
- The distance traveled from the time your brain tells your foot to move from the accelerator until your foot is actually pushing the brake pedal
- The distance your vehicle travels from the time your eyes see a hazard until your brain recognizes it
- The distance it takes to stop once the brakes are applied

#### Quote From The CDL Manual:

#### TruckingTruth's Advice:

- 1/8 second
- 2 seconds
- 1-2 seconds
- 3/4 second to 1 second

#### Quote From The CDL Manual:

The average driver has a reaction time of ¾ second to 1 second. At 55 mph this accounts for 61 feet traveled.

#### TruckingTruth's Advice:

Be sure to have reaction time and distance memorized. This will likely show up on your written exam.

- Reaction Distance
- Braking Distance
- Perception Distance
- None of these are correct

#### Quote From The CDL Manual:

Reaction distance is the distance traveled from the time your brain tells your foot to move from the accelerator until your foot is actually pushing the brake pedal. The average driver has a reaction time of 3/4 second. This accounts for an additional 60 feet traveled at 55 mph.

#### TruckingTruth's Advice:

Be sure to have the definition of Reaction Distance memorized.