A commercial driver is hauling freight across a desert highway where the ambient temperature has reached . During a scheduled en-route stop, the driver measures tire pressures and discovers that all tires are above their recommended cold inflation pressure, while several miles of the upcoming asphalt roadway show shiny, dark patches of bleeding tar. What is the correct procedure for managing both the tire condition and the driving surface hazards?
- ABleed the excess air from all tires to match the cold inflation specification, and increase travel speed over the bleeding tar to minimize tire contact time.
- BDouse the hot tires with cold water to restore standard pressure, and engage the engine retarder at its maximum setting when crossing the bleeding tar patches.
- Leave the tire pressures as they are without bleeding any air, drive at a reduced speed, and allow extra following distance when traversing the bleeding tar.Answer
- DDeflate the outer dual tires only to equalize axle loading, and apply firm snub braking directly within the bleeding tar sections to test pavement grip.
Answer
Leave the tire pressures as they are without bleeding any air, drive at a reduced speed, and allow extra following distance when traversing the bleeding tar.
Tire air pressure naturally increases with operating temperature, which is normal and accounted for by tire manufacturers. Drivers must never release air from hot tires because doing so results in severe under-inflation once the tires cool down, drastically increasing heat accumulation and blowout risk. In addition, intense heat causes road tar to bleed to the surface, creating slippery driving conditions that necessitate driving at reduced speeds with extended following distances.
Step-by-Step Solution
Key Concept
Hot Weather Tire Pressure Management and Road Surface Traction Hazards
Estimated Time:1m 30s