Visitors to Pikes Peak are advised to allow at least two hours for the 38-mile round trip to the summit and back, with uphill traffic always having the right-of-way and maintenance equipment on the road. Drivers climbing steeper grades should shift to a lower gear, and if an engine overheats, run it at a fast idle and consider cooling the radiator at water stations three, nine, 11, and 13 miles past the Gateway. On the descent, motorists should use a low gear so the engine can help brake the vehicle. Stops should be made in turnouts when possible, or otherwise on straight sections where the vehicle is clearly visible. Ranger personnel patrol the road whenever the highway is open and can be reached at 684-9138, and people with a history of severe cardiac or respiratory problems are advised not to travel to the summit. Visitors are also urged to care for the mountain by disposing of litter properly, not throwing ashes or cigar or cigarette butts from vehicles, and building fires only in fireplaces before making sure they are out.