2008 GMC Sierra 1500 Pickup Owner's Manual - Page 261

In recent years, more than 17,000 annual motor vehicle-related deaths have been associated with the use of alcohol, with about 250,000 people injured. 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. Braking See Brake System Warning Light on page 3-41. 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 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 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 the 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. The brakes might not have time to cool between hard stops. 4-3 Control of a Vehicle The following three systems help to control your 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 your vehicle. Adding non-dealer/non-retailer accessories can affect your vehicle's performance. See Accessories and Modifications on page 5-3.