GMC 2003 Envoy - Manual (Page 238)

You have three systems lhat make ypui veliide go ift^herg
you werit it to go. They arg the brakes, Ihe steering and
1he accaigraiof. Atl Thnee systems have to do their work a1
the places where the Ures nrieel the road.
Control of a Vehicle Braking
Braking action Involves pSfC&pSion lim e and
feaction Ume.
First, you have to decicfe to push on tho brake pedal.-
That’s peicepuon time. Then you have to bring up your
fool ar>d do it. That's raac/jon UrnSr
Average reatriorr /ime is about 3/4 of a sEcond. But
that's only an average It might be less with one driver
and as long as two or three seconds or more with
another. Age, physical oondilion, alertness, coordination
and gygsight alil play a part. So do alcohol, drugs and
Imstratlon. But even in 3^4 o! a second, a vahlqlq moving
at 60 mph {100 km/h) travels 66 feel (20 m) That
coutd be a lot of distance in an emergency, so keeping
enough space between yoiif vehicle and others Is
Imporiant.
And, of course, actus I stopping distances vary g ready
with Ihe surface of the road {wheJher it's pavement
Of gravel): the condiljon o1 the road (wet. dry, icy)- linR
tread, the condition of your brakes- ihe weight of
the vehicle and Ihe amount pf brake force applied
Scwnetimes, as whan youTa dnving on snow or ice. It's
easy to ask more of those control sysiems lhan the
liras and road can provide. That means you can lose
control of your vehicle.
4*5