1998 GMC Safari Owner's Manual - Page 190

I Braking Braking action involves perception time and reaction time. First, you have to decide to push on the brake pedal. That's perception time. Then you have to bring your up foot and doit. That's reaction time. Average reaction timeis about 3/4 of a second. But that's only an average. It might be less one driver with and as long as two or three seconds or more with another. Age, physical condition, alertness, coordination and eyesight all play part. So do alcohol,drugs and a frustration. But even in 3/4 of a second, a vehicle moving at 60 mph (100 k / ) m htravels 66 feet (20 m). That could be lot of distance in an emergency, so a keeping enough space between your vehicle and others is important. And, of course, actual stopping distances greatly vary with the surfaceof the road (whether it's pavement or gravel); the condition the road (wet, icy); tire of dry, tread; the condition your brakes; the weight the of of vehicle and the amount brake force applied. of Avoid needless heavy braking. Some people drive in spurts -- heavy acceleration followedby heavy braking -- rather than keeping pacewith traffic. Thisis a mistake. Your brakes may not have time to cool between hard stops.Your brakes will wear out much fasteryou if do a lot of heavy braking.If you keep pacewith 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're driving, brake normally but don't pump your brakes. If you do, the pedal may get harder to push down. your engine If stops, you will still have some power brake assist. But you will useit when you brake. Once the power assist is used up, it may take longer to and the brake pedal stop will be harder to push.