Control of a VehicleYou have three systems that make your vehiclego where you want it to go. They are the brakes,the steering, and the accelerator. All threesystems have to do their work at the places wherethe tires meet the road.Sometimes, as when you are driving on snow orice, it is easy to ask more of those control systemsthan the tires and road can provide. That meansyou can lose control of your vehicle. See TractionControl System (TCS) on page 329 andStabiliTrak® System on page 331.Adding non-GM accessories can affect yourvehicle’s performance. See Accessories andModifications on page 363.BrakingSee Brake System Warning Light on page 192.Braking action involves perception time andreaction time.First, you have to decide to push on the brakepedal. That is perception time. Then you have tobring up your foot and do it. That is reaction time.Average reaction time is about three-fourths of asecond. But that is only an average. It mightbe less with one driver and as long as two orthree seconds or more with another. Age, physicalcondition, alertness, coordination, and eyesightall play a part. So do alcohol, drugs, andfrustration. But even in three-fourths of a second,a vehicle moving at 60 mph (100 km/h) travels66 feet (20 m). That could be a lot of distance in anemergency, so keeping enough space betweenyour vehicle and others is important.And, of course, actual stopping distances varygreatly with the surface of the road, whether it ispavement or gravel; the condition of the road,whether it is wet, dry, or icy; tire tread; thecondition of the brakes; the weight of the vehicle;and the amount of brake force applied.326
