But the ability to drive is affected well below a BAC of
0.10 percent. Research shows that the driving skills
of many people are impaired at a BAC approaching
0.05 percent, and that the effects are worse at night. All
drivers are impaired at BAC levels above 0.05 percent.
Statistics show that the chance of being in a collision
increases sharply for drivers who have a BAC of
0.05 percent or above. A driver with a BAC level of
0.06 percent has doubled his or her chance of having a
collision. At a BAC level of 0.10 percent, the chance
of this driver having a collision is 12 times greater; at a
level of 0.15 percent, the chance is 25 times greater!
The body takes about an hour to rid itself of the alcohol
in one drink. No amount of coffee or number of cold
showers will speed that up. “I will be careful” is not the
right answer. What if there is an emergency, a need to
take sudden action, as when a child darts into the street?
A person with even a moderate BAC might not be able to
react quickly enough to avoid the collision.There is something else about drinking and driving that
many people do not know. Medical research shows that
alcohol in a person’s system can make crash injuries
worse, especially injuries to the brain, spinal cord, or
heart. This means that when anyone who has been
drinking — driver or passenger — is in a crash, that
person’s chance of being killed or permanently disabled
is higher than if the person had not been drinking.
{CAUTION:
Drinking and then driving is very dangerous.
Your re exes, perceptions, attentiveness, and
judgment can be affected by even a small
amount of alcohol. You can have a serious — or
even fatal — collision if you drive after drinking.
Please do not drink and drive or ride with a
driver who has been drinking. Ride home in a
cab; or if you are with a group, designate a
driver who will not drink.
4-5
Control of a Vehicle
You have three systems that make your vehicle go
where you want it to go. They are the brakes, the
steering, and the accelerator. All three systems have
to do their work at the places where the tires meet
the road.
Sometimes, as when you are driving on snow or ice, it
is easy to ask more of those control systems than
the tires and road can provide. That means you can lose
control of your vehicle. SeeStabiliTrak
®System on
page 4-11.
Adding non-GM accessories can affect your vehicle’s
performance. SeeAccessories and Modi cations
on page 5-3.
Braking
SeeBrake System Warning Light on page 3-39.
Braking action involves perception time and
reaction time.
First, you have to decide to push on the brake pedal.
That is perception time. Then you have to bring up your
foot and do it. That is reaction time.
Average reaction time is about three-fourths of a
second. But that is only an average. It might be less
with one driver and as long as two or three seconds ormore with another. Age, physical condition, alertness,
coordination, and eyesight all play a part. So do alcohol,
drugs, and frustration. But even in three-fourths of a
second, a vehicle moving at 60 mph (100 km/h) travels
66 feet (20 m). That could be a lot of distance in an
emergency, so keeping enough space between
your vehicle and others is important.
And, of course, actual stopping distances vary greatly
with the surface of the road, whether it is pavement
or gravel; the condition of the road, whether it is
wet, dry, or icy; tire tread; the condition of your brakes;
the weight of the vehicle; and the amount of brake
force applied.
Avoid needless heavy braking. Some people drive
in spurts — heavy acceleration followed by heavy
braking — rather than keeping pace with traffic. This is
a mistake. Your brakes may not have time to cool
between hard stops. Your brakes will wear out much
faster if you do a lot of heavy braking. If you keep pace
with the traffic and allow realistic following distances,
you will eliminate a lot of unnecessary braking.
That means better braking and longer brake life.
If your engine ever stops while you are driving, brake
normally but do not pump your brakes. If you do,
the pedal may get harder to push down. If your engine
stops, you will still have some power brake assist.
But you will use it when you brake. Once the power
assist is used up, it may take longer to stop and
the brake pedal will be harder to push.
4-6