What is the likely consequence when a trailer separates from the tractor and both air lines are disconnected?

When a trailer separates from the tractor and both air lines are disconnected, the likely outcome is that the trailer brakes will automatically engage. This is because most trailers are equipped with a braking system that activates when air pressure is lost. When the air lines disconnect, the trailer loses its air supply, which triggers the emergency brakes. The spring brakes on the trailer, designed for such situations, will engage, helping to bring the trailer to a stop. This safety feature is crucial for preventing further accidents and ensuring the trailer doesn’t roll away uncontrollably.

Understanding the mechanics behind this system is vital for safe vehicle operation, especially in large trucks and trailers where the potential for accidents increases if the trailer detaches. While the tractor may continue to move momentarily, the most significant safety mechanism involves the trailer's brakes engaging to prevent collateral damage or hazards on the roadway.