It is important for you to answer the following questions:
- What is the difference between the two types of
information our eyes provide?
- Where should a driver concentrate most of his or
her attention?
- What are the affects of alcohol on a driver’s
visual perception?
The skill of safe driving is mostly mental. It
is determined primarily by how well you think about
what is going on around you.
To think clearly and react quickly, you need information
and most of that information comes to you from your
eyes.
This is called visual perception and it means your
ability to notice many things at once.
To get the right information to the brain, a driver’s
eyes have to move constantly, picking out the appropriate
spots at the right time.
First, let's look at how a driver’s eyes work.
Our eyes provide two types of vision:
 |
Central vision |
|
Peripheral or side vision |
Our central vision covers about three degrees of our
visual field and peripheral vision or side vision covers
the rest.
| Now
as you can see here: |
 |
| The
three degrees of central vision is a very small
area in your total field of vision. But central
vision allows us to make very important judgment
like estimating distance and reading details
in the driving scene. |
Our peripheral vision is not as sharp as central vision,
but it is more sensitive to light and motion. And that’s
a good thing because it helps us detect events to the
side that are important to us, even when we’re
not looking directly at them. Events like this include
cars entering our field of vision from the side, or
warning lights from ambulances, police cars, and other
emergency vehicles.
Central vision plus side vision make up the entire
visual field, which is the main source of information
that all drivers need for safe driving. Most driver
mistakes are caused by bad habits in the way drivers
use their eyes.
There are three basic rules to follow when developing
good eye habits for driving:
| Aim
high |
Look ahead, not down; the experienced driver’s
attention is focused on the road ahead with their
central vision following the intended path of travel. |
| Keep
your eyes moving |
A good driver concentrates on selecting details
in the traffic scene and on the distance between
his/her car and objects ahead. |
| Get
the big picture |
Search the whole scene; check the rear view mirrors. |
As you approach an intersection, watch for vehicles
and pedestrians moving in both directions, for traffic
control devices, and for anything else that might block
your vision or otherwise increase risks.
Now let's see how these rules work in some common driving
situations.
We know that driving is primarily a task of information
processing, but in order for us to learn which visual
cues are important to us for driving, we must be able
to describe a driver’s visual search process.
| This is a picture
of the driver’s visual field: |
 |
| The oval area in
the middle represents the driver’s central
vision. The gray area surrounding the central
vision oval represents peripheral or side vision.
|
When we drive our eyes move in a series of rapid, jerky
movements. Between each movement, our eye pauses for
a fraction of a second, then darts to another part of
the scene. These pauses are known as fixations. Even
though these fixations are very short, they give the
driver’s brain time to gather important information
from the eye’s image of the driving scene.
Below are examples of how the eyes of an experienced
driver cover the driving scene when confronted with
two potentially hazardous driving situations: negotiating
a curve and merging onto a freeway.
The same three rules that apply to training your vision
apply here:
