GMC 2010 GMC Yukon/Yukon XL, Owner'S Manual

Page: 365 / 614

For persons under 21, it is against the law in every
U.S. state to drink alcohol. There are good medical,
psychological, and developmental reasons for
these laws.
The obvious way to eliminate the leading highway
safety problem is for people never to drink alcohol
and then drive.
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.
Control of a Vehicle
The following three systems help to control the vehicle
while driving
— brakes, steering, and accelerator.
At times, as when driving on snow or ice, it is easy to
ask more of those control systems than the tires and
road can provide. Meaning, you can lose control of
the vehicle. See
StabiliTrak
®
System on page 5 ‑ 6 .
Adding non ‐ dealer/non ‐ retailer accessories can
affect vehicle performance. See Accessories and
Modifications on page 6 ‑ 4 .
Braking
If the vehicle is a Two ‐ mode Hybrid, see the Two ‐ mode
Hybrid manual for more information.
See Brake System Warning Light on page 4 ‑ 36 .
Braking action involves perception time and reaction
time. Deciding to push the brake pedal is perception
time. Actually doing it 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 or
more 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 100 km/h (60 mph) travels
20 m (66 feet). That could be a lot of distance in an
emergency, so keeping enough space between the
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 the brakes; the weight
of the vehicle; and the amount of brake force applied.
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