2004 GMC Sierra 1500 Pickup Owner's Manual - Page 341

Then here are some tips: Hill and Mountain Roads • Make sure your vehicle is well ventilated, with a comfortably cool interior. • Keep your eyes moving. Scan the road ahead and to the sides. Check your mirrors and your instruments frequently. • If you get sleepy, pull off the road into a rest, service or parking area and take a nap, get some exercise, or both. For safety, treat drowsiness on the highway as an emergency. Driving on steep hills or mountains is different from driving in flat or rolling terrain. 4-45