Is it legal to coast downhill with a truck out of gear?

Coasting downhill with a truck out of gear is considered illegal because it compromises vehicle control and safety. When a truck is in gear, the engine provides resistance that helps to control speed, particularly on downhill grades. This resistance, known as engine braking, allows the driver to maintain better control of the vehicle and reduces reliance on the braking system, which can overheat and fail if used excessively.

Additionally, operating a vehicle out of gear can lead to an unintended acceleration scenario where the driver cannot quickly respond to hazards, such as a sudden stop or turn in the road. Laws regarding vehicle operation are often designed to enhance safety for all road users, and coasting poses an increased risk for accidents. Hence, it is illegal in most jurisdictions to coast downhill with the vehicle out of gear.