Identify, Predict, Decide and Execute. These are steps involved in the proper reasoning process that insures safe vehicle operation. These principles make for good defensive driving, and address the complexities of visual perception in traffic. Driving is such a regular part of most people’s lives that we’re figuratively asleep at the wheel. This wake-up call to awareness will help you avoid citations, and even more importantly, avoid collisions.

The IPDE Process and Defensive Driving

"IPDE" is an organized thinking-doing process that you should use over and over again when you are driving.

The four steps of the IPDE process are:

IPDE can help you avoid collisions. Take a moment to think through the IPDE process and how you should use it while driving. IPDE can help you become a "defensive driver." Defensive driving is the art of protecting yourself and others from dangerous and unexpected changes in the driving environment.

Defensive drivers anticipate the actions of other road users and are willing to adjust their own speed and position if they make any mistakes. Defensive drivers also adjust their driving practices to reflect changes in weather and road conditions. With practice, the IPDE process will become automatic.

Driving Distractions and the "Big Picture"

As a driver, you have a responsibility to your passengers and to yourself to concentrate all of your attention on the "big picture" of what is happening around your vehicle while you are driving. Distractions can steal part or all of this big picture. If you turn your head in conversation with a passenger, open up a beverage, or look around for something on the seat next to you, the results can be disastrous.

These distractions, coupled with your surroundings inside the car (including passengers, door posts, roof supports, packages piled on a rear seat) all conspire to limit your field of vision.

Mental distractions whether you are rehearsing a speech, planning your day, or dozing at the wheel force you to "tune out" what is happening around you in traffic and tune you into trouble.

You won’t simply have lost the big picture of your surroundings, you may have lost your life.

If it is important for you to discuss something with a passenger or on the phone, park your car and then talk. Don't turn your head or get caught up in conversation and risk losing your traffic picture.

Unrestrained children, pets, and even the radio will distract you while driving – driving is a full time job.

It is always against the law for automobile drivers to wear headphones or earplugs while driving.

We have all heard of people who were "driving too fast for the conditions." This simply means that the weather or road conditions or the condition of the vehicle or driver demanded a slower speed for safety reasons.

In most cases, it is really "perception too poor for conditions" that causes more accidents than speed alone. Poor visibility or distractions that have shrunk your view of the "big picture" call for you to reduce your speed or stop the car.

Never concentrate too long on any one part of the picture. A fixed stare will cancel out your ability to see the "big picture."

If drivers or pedestrians are preoccupied or distracted, they can be totally unaware of your presence. It is up to you to see them and alert them so that they see you. But do not blast your horn as a last minute warning: this might only frighten them, which could lead to an accident. Instead, use an early gentle tap of the horn, or flick your lights to get their attention and make certain, by eye contact, that the person sees you.

Scene of an Accident

One of the more dangerous distractions is an accident that has already happened. "Rubber Necking," or gawking, is a dangerous problem that we all have witnessed.

When police officers arrive at the scene of an accident, after they have determined if someone is injured and helped them, they will work to quickly clear the accident and direct traffic safely around it. If you are the first person at an accident scene, you should stop after you pass the accident and determine if your assistance is needed.

Accidents and Your Condition

Your personality, your mental condition, and your physical condition all affect the way you drive. Never let your emotions interfere with safe driving. Always strive to use good judgement, common sense, courtesy, and the principles of defensive driving when you are on the road.

Some physical ailments, such as poor vision, heart problems, or epilepsy may affect your driving. Try not to drive when you are ill. Discuss your condition with your physician and follow his or her advice as to whether or not you should drive. If you have a condition that might affect your ability to drive safely, you should also inform the DMV.

Conditions Your Physicians Should Report

Although not required by law, your doctor may report any other medical condition that they believe may impair a patient's ability to drive safely.

Remember:

1. Never drive after drinking or using drugs and never ride with anyone who has been drinking or using drugs.
2. If you are either ill or upset, don't drive. Your emotions, like anger, worry, etc., can make you drive unsafely. Never vent your anger by driving recklessly.

It is illegal to drive when you are impaired, no matter what the reason may be.

Defensive Driving and Perception Techniques

These are the key things to remember as you practice defensive driving:

• "Aim High" in steering;
• Get the big picture;
• Keep your eyes moving;
• Leave yourself an "out;"
• Make sure that others see you.

The length of time it takes a driver to identify a situation is called perception time. Perception time depends on visibility, the driver's physical condition, and the road situation. Effectively searching down the road will shorten your required perception time.

Many drivers fail to notice what is happening on or near the roadway. Some drivers interpret information incorrectly and, as a result, make mistakes. To avoid errors and make the best driving decisions, you must learn to gather and correctly interpret information that relates to driving.

There are four basic categories of information you'll need to process:

How to Search and the Four-Second Rule

Developing skills for searching the roadway and responding to the conditions that you observe is one of the most important driving skills.

Search the area in and near your intended path of travel four seconds ahead. Problems in this area develop quickly. Next, search at least twelve seconds ahead. This way, if there are possible conflicts, you will have ample time to respond. Having this time to make a good decision will reduce the likelihood of your making a bad decision.

When we drive, our vision is somewhat limited. We cannot even process everything we see, therefore we must search the road for things with collision potential. Things that move, -- such as vehicles, pedestrians, and animals -- are more dangerous than fixed objects. Things that are immediately in your path are more dangerous than those farther away.

The crests of hills, curves, large vehicles, shrubbery and buildings can prevent you from seeing important objects. Limited visibility should alert you to the possibility of trouble while you are driving.

Along the road there are signs and signals that will guide you or warn you of any upcoming hazards or route changes. Select your speed and position accordingly. Make sure you have at least three seconds between you and the vehicles ahead of you. Also check the space between your car and any vehicles in the lane next to you. Use your rearview mirror and side mirrors every three to five seconds. After a quick check of the mirrors or a fast look over your shoulder to check behind you, return your attention to the path immediately ahead of you. If this is not enough time, don't stare. If there is no immediate problem in the path ahead, check the mirrors or look over your shoulder again as needed.

Checking traffic to the sides and the rear in this manner is a critical habit to develop.

You should also glance at your instrument panel often to ensure there are no problems with the vehicle and to verify that you know what your speed is. Determine what your gauges tell you and then quickly return your attention to your path of travel.

Using Your Eyes Effectively

It is important to answer the following questions.

What is the difference between the two types of information our eyes provide?

1. Where should a driver concentrate most of his or her attention?
2. What are the effects of the alcohol on a driver’s visual perception?

The skill of safe driving is mostly in the mind. 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:

1. Central vision
2. Peripheral or side vision

Our central vision covers about three degrees of our visual field and peripheral vision or side vision covers the rest.

This is a picture of the driver's visual field:

The oval area in the middle represents the driver's central vision. The black area surrounding the central vision oval represents peripheral or side vision.

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, such as cars on cither 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:

1. Aim high. Look ahead, not down. The Experienced drivers focus their attention on the road ahead with their central vision following the intended path of travel.
2. 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.
3. Get the big picture. Search the whole scene; check the rearview mirrors.

As you approach an intersection, watch for vehicles and pedestrians 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.

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:

Merging is a potentially difficult maneuver.

A good driver starts evaluating the conditions in a stream of traffic ten seconds before reaching the merge point. In a merge situation, experienced drivers maintain lane position by glancing momentarily to the right side of the road and always maintain an awareness of other traffic patterns developing around them.

Train your eyes to follow the three rules:

• Aim high – look ahead, not down;
• Keep your eyes moving;
• Get the big picture.

Keep these rules in mind whenever you drive and your eye habits will improve.

With experience, some driving tasks don’t require every eye fixation to be directed only toward traffic and the path of the car.

In this situation, for example, a driver is concerned with avoiding a pedestrian, but is still able to maintain control of the vehicle by using only very brief glances along the intended path of travel.

Let’s look at two examples in which drivers are functioning at less than peak efficiency.

This driver is tired. Notice how his central vision tends to fixate lower and to the right, often dipping all the way down to the road surface.

This driver is under the influence of alcohol. His example allows us to answer our third question – what is the effect of alcohol on visual perception?

After only a few drinks the effects of alcohol on his eye habits are readily noticeable. His concentration is failing, his eyes are staring straight ahead, and his central vision is stuck squarely on the center of the road. He notices nothing on either side, which creates a very dangerous situation, both for himself and every other driver on the road.