Adverse Conditions

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Driving ProblemsCaused by Reduced Visibility Traction

& Space

Click for Version & Contact Information

Adverse Conditions

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Adverse Conditions

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Adverse Conditions Clip: Very Adverse Conditions!

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Adverse Conditions

General InfoSkid Control & P

reventionAntilock Brake S

ystemsHydroplaningWinter DrivingFog DrivingNight Driving

Contents

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Adverse Conditions

Nearly 1 million crashes occur every year due to reduced traction under adverse driving conditions. [NHTSA]

These are caused by drivers who fail to adjust techniques to account for adverse conditions. [NHTSA]

Accident Facts

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Adverse Conditions Preventable?

Would your driving habits change if you knew this was going

to happen?Why not drive

differently all the time?

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Adverse Conditions

To drive safely, you have to recognize the demands that you, your vehicle, & your tires face.

Many motorists fail to adjust their techniques – setting the stage for loss of control.

Recognition

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Adverse Conditions Recognition

How much time should be built into your trip

when weather conditions change?

What happens if you don’t adjust your

schedule?

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Adverse Conditions Perception, Recognition,

Response

How much traction is

available to you at this moment?

How would you know

that?

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Adverse Conditions

Drive more slowly: As your speed decreases, the tire

footprint increases, providing better traction

Maintain a safe distance: 2X or 3X the normal space cushion

Be extra alert at intersections: Check for other vehicles that are

not adjusting for current conditions

Driving in Adverse Conditions

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Adverse Conditions

Know the performance characteristics of your tires: Tires are

designed for differing levels of performance under various weather, temperature & wear conditions

Tire Performance

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Adverse Conditions

Tires cannot provide good wet traction once the tread depth is worn below 1/16 of an inch

Check tires twice a month for wear & tear with the penny test

Maintain proper air pressure at all times

Tire Maintenance

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Adverse Conditions

Think ahead about your driving: Know the adjustments

needed for current weather conditions

Be knowledgeable about your tires: Make sure your vehicle is

equipped with the correct performance tires;

When in doubt ask a tire dealer for information

Smart Thinking!

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Adverse Conditions

Drive smoothly: Avoid abrupt braking,

accelerating, or turning

Plan your braking: Slow down prior to a

curve or a hill; This will reduce your

braking distance while increasing traction

Planning Ahead

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Adverse Conditions Accident Facts

You will likely experience situations that will lead to collisions!

If you don’t build extra space or time into adverse conditions…

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Adverse Conditions Timing is Everything When would be the best time to adjust speed or position as you

approach curves?Why?

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Adverse Conditions

Is this trip necessary? Can the trip be delayed

until traction improves?Can the trip be

accomplished another way (phone, Internet)?

Can different trips be combined to minimize traffic & environmental exposure?

Alternatives

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Adverse Conditions

Get the proper mental state: The ability to focus

is essentialGet proper rest:

Help maintain the alertness needed to handle the extra demands & increased reaction times

Driver Readiness

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Adverse Conditions

Know the weather forecast before you get on the highway

Keep your windshield wipers in good condition

Check windshield washer fluid regularly

Vehicle Readiness

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Adverse Conditions

Test both low beams & high beams before a trip

Have your headlights checked annually for proper orientation & focus

Check fluid levels, tire pressure, lights, & battery

Have a mechanic give your vehicle a winter readiness check

Vehicle Readiness

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Adverse Conditions

Always use your safety belt!

Turn your headlights on

Bridges & overpasses freeze before other roadways do

Don’t Forget

Adverse Conditions

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Skid Control & Prevention

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Adverse Conditions

Skids happen whenever tires lose their grip on the road

Tires lose their grip for 1 of 4 reasons: Overbraking Oversteering Overacceleration Driving too fast

Why Skids Happen

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Adverse Conditions

Overbraking: Braking too hard &

locking up the wheels;

Braking when the road is slippery

Oversteering: Turning the wheels

more sharply than the vehicle can turn

Overacceleration: Supplying too

much power to the drive wheels, causing them to spin

Driving too fast: Approaching

hazards so quickly that there is no time to recognize & react properly

Why Skids Happen

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Adverse Conditions

Skidding occurs whenever the force applied to the tire exceeds the tire’s traction

Your goal must be to keep the tires below the threshold of skidding

Even the best skid-control skills won’t prevent a collision if the available room is less than the space required to stop or escape

Skid Control

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Adverse Conditions Skid Control

How do you keep your car

below the threshold of

skidding?How do you

steer out of a skid?

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Adverse Conditions

Most skids, spins, & slides happen on wet, icy, or snow-packed surfaces

Loss of control can also happen on dry surfaces when you combine high speeds with quick changes in direction

Skids on Dry Surfaces

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Adverse Conditions

Once your vehicle skids more than 45° you cannot recover control

Skid recovery is an acquired skill that must be practiced if you are going to be confident in real-life situations

Skid Practice

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Adverse Conditions

Skid recovery calls for an unnatural response by the driver

Find a deserted parking lot with no obstructions

Skid Practice

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Adverse Conditions Clip: Skid Practice

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Adverse Conditions Skid Prevention

Explain why skid

prevention is the key to

skid control.How would

you apply this strategy?

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Adverse Conditions

Your exit options are reduced when you tailgate

A skid or a slide can result because you are unable to adjust speed, space, or direction in a controlled manner

Tailgating

Adverse Conditions

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Antilock Brake

Systems

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Adverse Conditions

Antilock brake systems can stop more quickly than conventional brakes on wet, icy, & snow-packed roads

Antilock brakes prevent the wheels from locking during emergency braking situations

Antilock brakes allow drivers to maintain steering control

Check the dashboard for the ABS symbol

Antilock Brakes

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Adverse Conditions

When used properly, 4-wheel ABS is a safe, effective braking system

Antilock brakes cannot compensate for aggressive driving

Antilock brakes cannot guarantee recovery from a skid

Avoid extreme steering manuevers while your ABS is engaged

Antilock Brakes

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Adverse Conditions

4-wheel ABS: Generally found on passenger

cars; Designed to maintain steering

ability in emergency braking situations

Rear-wheel ABS: Found exclusively on light trucks; Designed to prevent the vehicle

from skidding laterally

2 Types of ABS

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Adverse Conditions

Antilock brakes are less effective on certain roadways: Extremely icy roads; Freshly fallen snow; Gravel roads

Don’t count on the ABS—continue to drive cautiously

ABS Shortcomings

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Adverse Conditions

Do maintain firm & continuous pressure on the brake while steering to enable 4-wheel ABS to work properly

Do allow enough distance to stop: Follow 4 or more seconds

behind vehicles if conditions are good;

Follow 6 or more seconds if conditions are adverse

ABS Do’s

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Adverse Conditions

Do practice with ABS in empty parking lots to become familiar with the pedal pulsations

Do consult the owner’s manual for additional instructions

ABS Do’s

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Adverse Conditions

Don’t drive an ABS-equipped vehicle more aggressively

Don’t pump the brakes: Pumping the brake

turns the ABS system on & off

Don’t be alarmed by the noises & pedal pulsations

Don’t forget to steer

ABS Don’ts

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Adverse Conditions Antilock Brakes What can ABS do for

you?What can’t it do for you?What can you do to remember this vital

information?

Adverse Conditions

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Hydroplaning

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Adverse Conditions

During a heavy downpour, water on the pavement can cause your vehicle to hydroplane

Your front wheels ride on a wedge of pressurized water & rise off the road surface

Hydroplaning

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Adverse Conditions

Since your wheels no longer contact the road, you will experience a partial or total loss of steering control

The only solution is to reduce speed: Gently reduce

pressure on the accelerator to bring the speed down

Hydroplaning

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Adverse Conditions

When rainfall begins, water mixes with oil & debris from the pavement, creating very slick conditions

Drivers often forget this potential hazard, creating dangerous situations

Reduce speed & test traction early & often

Summer Icing

Adverse Conditions

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Winter Driving

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Adverse Conditions Enough Space Time & Traction?

How do multicar collisions happen?

What should have been

done to prevent this

from happening?

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Adverse Conditions

Most drivers realize that winter driving is different, but lack the comprehensive knowledge to handle changing environments

Drivers must stay informed about current weather conditions, and how these conditions will likely change

Awareness

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Adverse Conditions

Failing to allow enough time to stop your vehicle is a major cause of winter driving crashes

Slippery driving conditions can triple stopping distances

Slowing your cruising speed, anticipating stops & slowdowns, and increasing coast & brake times will help ensure collision-free stops

Braking

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Adverse Conditions

Accelerating, turning, & passing present dangers during winter: Accelerate slowly to avoid loss of

traction & subsequent loss of control; Turn slowly with caution to avoid

sliding into a stationary object or the path of an oncoming vehicle;

Pass with care because passing lanes are not maintained as well;

Avoid sudden or swift movements Triple your following distance so

there’s plenty of room to see & maneuver

Control

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Adverse Conditions Clip: Winter2-Lane Driving

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Adverse Conditions

For every 10° drop in outdoor temperature, the air pressure inside your tires drops 1-2 psi

Regularly check tires for proper air pressure

Never reduce air pressure in an attempt to increase traction on snow or ice—your tires could be seriously damaged

If you get stuck, a spinning tire could explode when your speedometer reads over 35 mph

Winter Driving & Tire Pressure

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Adverse Conditions Road Salt

When does salt stop working?

Why would you need to know that?How could

you tell if the salt was

becoming ineffective?

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Adverse Conditions Clip: WinterCity Driving

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Adverse Conditions Traction, Space, & Visibility Changes

How much traction is

available to you at this moment?

Why should you test traction

before the curve?

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Adverse Conditions

If a tow truck is not readily available, gently rock your vehicle back & forth

Repeatedly shift back & forth from drive to reverse, until momentum carries you out of the problem area

Rocking the Car

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Adverse Conditions Clip: Winter Highway Driving

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Adverse Conditions

Although water freezes at 32°, road surfaces can freeze when the air temperature is as high as 40°

Ice on roads is generally classified as either white ice or black ice

Icy Roads

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Adverse Conditions

White ice is usually visible to the eye

White ice is usually created in 1 of 2 ways: Compacted

snowfall that has slightly melted & then frozen;

Rainfall that freezes

White Ice

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Adverse Conditions

Black ice is usually not seen until the vehicle is already on it

Black ice is usually created by clear water or condensation that has frozen on dark pavement

Black ice usually forms below overpasses, on bridges, in areas of run-off, in shaded areas, or anywhere the ground is below 40 degrees

Good pavement conditions located just before these areas can lull you into a false sense of security

Black Ice

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Adverse Conditions White Ice orBlack Ice?How do you

know if there’s black or white ice under the

snow cover?When do you

need the answer?

What strategies are needed

here?

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Adverse Conditions Clip: Black Ice

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Adverse Conditions Ice Storms

Describe your thoughts as you navigate

this road.What kinds of conflicts do

you anticipate

here?

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Adverse Conditions

Heavy clothes & Blanket Traction material (sand,

kitty litter) Tire chains Small shovel First aid kit Flashlight Jumper cables Bright cloth to use as an

identifying flag

Winter Driving Emergency Kit

End of Part One

Presentation Version 1.1Released 2004-10-23

Professional Education Designs2629 Shannon CourtDarien IL 60561

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Adverse Conditions