partial lesson first 19 out 45 slides. human physical and psychological issues of driving

Partial Lesson

first 19 out 45 slides

Human Physical and Psychological Issues of Driving

Human Physical and Psychological Issues of Driving

Purpose: To become acquainted with the important physical and psychological issues of the driver, including vision, hearing, emotional state and and introduction to the effects of alcohol and drugs.

This lesson will be divided into two parts.

Physical Senses and Driving

The physical nature of the driver

In order to drive safely, you must be in good physical condition. In particular, you need to be able to see and hear well enough to detect potential hazards and handle emergency situations.

What are some specific abilities needed for safe driving?

Let’s now consider

visual acuity


visual acuity

Vision plays a key role in the steps by which you detect and avoid a hazardous situation which include:

Vision plays a key role in the steps by which you detect and avoid a hazardous situation which include:

a) the transmission of a visual image to your brain,

b) the comparison of this image with learned rules and experiences,

c) a decision to take an action, and d) the transmission through your nervous system of commands

to your hands and feet to turn the steering wheel, apply brakes, accelerate or decelerate, use the horn, etc.

Good vision is key to being able to stop your vehicle in time to avoid a

collision.



peripheral vision


peripheral vision

Visual acuity is sharpness of vision…it’s your central vision which discerns the clearest details which may be perceived.

A person who can read 3/8-inch high letters clearly from a distance of 20 feet is considered to have normal vision and is said to have _____vision.

A person with 20/40 vision must be 20 feet from the eye chart to read what a person with normal vision would be able to read at 40 feet.

And so when it comes to driving, visual acuity is very important for reading road signs and identifying hazards.

The DMV uses Snellen wall charts and optical devices to test eyes. Your vision must be at least 20/40 with or without correction.

You can compensate for

poor visual acuity by wearing glasses or contact lenses


Peripheral vision or side vision is the field of view that surrounds the central portion of the visual field.

If your side vision is very poor it can seriously affect safe driving, unless…

You can see things most clearly directly ahead, while things to each side (your peripheral vision) are less distinct.

…you compensate for it by increased scanning and visual searching (turning of head)


Peripheral vision: It helps detect signs, hazards, and changes in the traffic flow. As a driver, when you notice something important, you will move your eyes or head to look at the object or situation.

You will also use peripheral vision to monitor traffic in front when looking in your rear view mirror…

Peripheral vision also helps keep the vehicle centered in the lane as it monitors your lane boundaries.


Poor peripheral vision can result in: a) failing to see or obey a traffic light. b) failing to react to a hazard coming from the left

or the right; weaving on a curve; or driving too close to parked cars.

No matter how good your peripheral vision, there will still be areas to the sides and behind your vehicle…

…that cannot be seen. These areas are referred to as blind spots.


Other vehicles, especially compact cars and motorcycles are easily hidden in your blind spots. Your mirrors will not eliminate all blind spots.

This car will soon disappear into a blind spot

Therefore, when lane changing, you need to check for vehicles in your blind spots by turning your head and and looking into the lane you want to enter.

Large vehicles such as trucks have more extensive blind spots than smaller vehicles.


Other vehicles, especially compact cars and motorcycles are easily hidden in your blind spots. Your mirrors will not eliminate all blind spots.

Do not linger in blind spots!

Therefore, when lane changing, you need to check for vehicles in your blind spots by turning your head and and looking into the lane you want to enter.

Large vehicles such as trucks have more extensive blind spots than smaller vehicles.


Depth perception is the ability to correctly perceive the distances of objects in

relation to your own position.

“It’s tight, but I think I can…”


Depth perception is the ability to correctly perceive the distances of objects in

relation to your own position.

Poor depth perception can result in:

a) stopping too short of limit lines or inside intersections

b) turning too wide or too short

c) being unable to maintain a constant speed, or

d) being unable to follow other vehicles at a distance appropriate for driving conditions

Depth perception is also important when passing, turning and parking.

With parked cars on both sides, it is a little tight. Which vehicles will you move closer to and WHY?

Vehicles on the left side. You have better depth perception on your left side because you are

sitting on that side of your car.

A person can compensate for poor depth perception by using extra caution in judging

the speed and distance of on-coming vehicles and approaching objects.


Night vision refers to your ability to see well in low light levels and is necessary for

being able to drive safely at night.

Poor night vision can result in:

a) not being able to react to hazards in front of your car in time.

b) tailgating c) failing to steer in the

proper direction when necessary to avoid low contrast road features such as the edge of the roadway and other irregularities in the road surface.

The visual ability of two drivers may be about the same during daylight hours,

but can be very different at night.


Night vision refers to your ability to see well in low light levels and is necessary for

being able to drive safely at night.

Driving safely at night also requires being able to see low contrast objects.

What could this pedestrian have done to be more visible?

A person wearing dark clothing and crossing the street in front of a driver is much harder to detect at night because there is much less contrast at night with the dark background.

Wear lighter colored clothing.


Glare is intense and blinding light Glare is intense and blinding light

Glare resistance is the extent to which a driver can still see objects and events while facing a steady source of glare such as on-coming headlights or a setting sun.

For example, glare caused by the brightness of on-coming headlights can prevent a driver from seeing an approaching vehicle or pedestrian crossing the roadway.

If on-coming cars are blinding you with their bright lights, where should you look

to avoid the direct, bright glare?

The white edge line.



Glare recovery is the speed with which a driver’s vision returns to normal

after being exposed to glare such as the brightness of a low sun.

STOPand

THINK

What effect would a dirty

windshieldhave with sun glare?

It would make everything much

harder to see.

Both glare resistance and recovery is important for being able to drive safely during sunset or at night.


What could she do to minimize the direct sun glare?

Drop the sun visor / use sunglasses


Poor glare resistance and recovery can result in a driver being blinded by a glare source which can result:

a) in missing curves in the road

b) striking unobserved pedestrians

c) crashing into the rear of a slow moving, stalled, or stopped vehicle Glare resistance and recovery

deteriorate with age; also, older drivers must drive more cautiously at night.


partial lesson first 19 out 45 slides. human physical and psychological issues of driving

Documents

visual acuity vision

good vision

central vision

normal vision

poor peripheral vision

safe driving

head physical senses

poor visual acuity