Friction
The only contact your car has with the highway is through the tires; and it is the
friction between the tires and the highway that enables you to start, stop, and
control the car. This contact is about equal to the length of the palm of your hand.
On a wet or slippery road, this friction is greatly reduced, and it becomes more
difficult to stop or control a vehicle.
Stopping on Ice
If you apply your breaks suddenly on an icy road, your vehicle will go into a skid. If
you have to stop on a slippery surface, it is advisable to keep the clutch engaged
and to pump the brake pedal in and out, gradually slowing the vehicle without locking
the wheels. The use of studded tires decreases stopping distance on ice. You may
wish to use neutral in certain stopping situations; the use of neutral takes the power
away from the drive wheels which allows you to have more control.
Rain
Many drivers do not realize that roads are likely to be especially slick just after it
begins to rain or drizzle. The first few drops loosen the grease and dirt accumulation
on the surface of the road. The loosened grease and dirt mix with the raindrops, and
the road is quickly covered with a slippery film that makes it extremely dangerous.
The first few drops of rain are danger signals telling you to slow down and use extra
caution. Don't turn your windshield wipers on with the very first sign of rain. Allow a
slight buildup of rain which will assist cleaning the windshield and eliminate smearing.
Hydroplaning
Hydroplaning takes place on wet roads. As speed increases, your tires start to ride
up on a film of water. In a standard passenger car, partial hydroplaning starts at
about 55 km/h at which point the tires may be totally up on the water. In a severe
rainstorm, for example, the tires lose all contact with the road at 85 km/h. When this
is the case, there is no friction available to brake, accelerate, or corner. A gust of
wind, a change of road camber, or a slight turn can create an unpredictable and
uncontrollable skid.
The best thing to do is to take your foot off the accelerator and let the car slow
down. If you skid while your car is only partially hydroplaning, you should be able to
get control by correcting for the particular type of skid that occurs. On the other
hand, if you are totally hydroplaning, about all that you can do is release the
accelerator and ride out the skid.
To prevent hydroplaning, it is most helpful to have good tires with deep treads. The
treads allow the water to escape from under the tires and tend to prevent complete
hydroplaning at normal highway speeds. However, when the depth of the water
exceeds the depth of the treads, complete hydroplaning can be expected at speeds
from 80 to 90 km/h.
Skids
When tire grip fails, skidding occurs and the driver loses control. Drivers cause
skidding by:
1. excessive speed
2. excessive acceleration
3. sudden and/or excessive braking
4. rough steering
To correct a rear-wheel skid, remove your feet from the pedals and steer in the
direction of the skid.
To correct a four-wheel skid, release the brake, re-apply it gently and increase
pressure slowly to avoid locking the wheels again.
ABS Brakes
Most newer vehicles are equipped with Antilock Braking Systems. They allow a driver
to steer their vehicle while braking. Don't be surprised if you hear a strange noise or
feel thumping on the break pedal. This is the sound and feel of the computer giving
commands to the braking wheel which is coming in contact with the road surface.
Front-Wheel Drive Vehicles (FWDV)
Experienced FWDV drivers may find that gentle acceleration will help the vehicle pull
out of a rear wheel skid. If the front wheels skid, take your foot off the accelerator.
The braking effect of the engine may slow the car to the point where front-end
traction is regained. If the skid continues, depress the clutch or select neutral.
Freely rolling wheels are better able to regain traction.
The use of "similar" tires on all four wheels of a front-wheel drive vehicle is
recommended. It is very dangerous to mix bias ply and radial ply tires. Usually
all-season type tires are adequate, except in heavy snow areas. If you are installing
snow tires make sure they are the same on all four wheels. The same applies to
all-season and conventional tires.
Rules for Winter Driving
1. ACCEPT YOUR RESPONSIBILITY to do all in your power to drive without
accident. Do not blame the weather for a crash. Be prepared to meet any
situation.
2. ADJUST YOUR SPEED TO CONDITIONS. Slow down on wet, snow-covered, or
icy roads so you can stop in time if you have to. Watch for ice patches,
especially in shaded area, on bridges, and on overpasses.
3. GET THE "FEEL" OF THE ROAD. If you are away from traffic try the brakes
occasionally while driving slowly. Find out just how slippery the road is and
adjust your speed to roadand weather conditions. Never make sudden moves
like slamming on brakes or accelerator. Downshift the gears to slow down for a
stop.
4. KEEP THE WINDSHIELD CLEAR OF SNOW, ICE, AND FOG. Be sure headlights,
windshield wiper blades and defrosters are in top working condition. You have
to see danger to avoid it.
5. USE SNOW TIRES, TIRE CHAINS, OR STUDDED TIRES ON SNOW AND ICE. They
cut stopping distances and give more starting and climbing traction ability.
However, even with the help of chains or studs, slower-than-normal-speeds
are a "must" on snow and ice.
6. PUMP YOUR BRAKES TO SLOW DOWN OR STOP. Slamming on the brakes can
lock the wheels and throw you into a dangerous skid.
7. FOLLOW AT A SAFE DISTANCE. Keep well back of the vehicle ahead of you in
order to give yourself room to stop. Remember, without tire chains, it takes 3
to 12 times the distance to stop on snow and ice as on dry concrete.
8. REMEMBER CONDENSATION ON THE PAVEMENT OF BRIDGES AND OVER-PASSES
FREEZES BEFORE THE REST OF THE ROADWAY.
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