What is the purpose of placing the tractor transmission in neutral after uncoupling?

Placing the tractor transmission in neutral after uncoupling serves the important purpose of avoiding accidental rolling. When the transmission is in neutral, the engine is disengaged from the wheels, preventing any unintended movement of the tractor. This safety measure is crucial, especially on inclines or uneven surfaces, where a vehicle could roll unexpectedly without proper control. Ensuring that the transmission is neutral offers peace of mind and allows for safe positioning of the tractor, especially during the transition between trailers.

The other options focus on different aspects of vehicle operation. Engaging the brakes is essential when coming to a complete stop, but rolling prevention is more directly accomplished through the transmission being in neutral. Easier maneuvering is related but secondary to the primary safety concerns. Preparing for coupling another trailer is part of the operational process, yet it does not directly address the immediate safety benefit gained from putting the transmission in neutral.