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Hot Weather Driving

Hot Weather Driving is a required knowledge area under 49 CFR 383.111(a)(12)(ii). The tire pressure rule tested here, that a hot tire's measured pressure reads higher than its true cold pressure by a defined correction amount, is directly codified at 49 CFR 393.75(i).

Practice Hot Weather Driving

5 Questions

  1. A driver checks a tire during a stop in extreme heat and finds the measured air pressure is higher than the vehicle's specified cold inflation pressure. What does 49 CFR 393.75(i) say the driver should do?
  2. What is the safe procedure for checking engine coolant on a vehicle that does not have a sight glass or coolant recovery container, after driving in very hot weather?
  3. Why does very hot weather create a road-surface hazard called "bleeding tar"?
  4. In desert conditions during very hot weather, why does guidance advise driving slower than usual, apart from any posted speed limit?
  5. While driving in very hot weather, the coolant temperature gauge climbs above the highest safe mark on the gauge. What should the driver do?