In a two-trailer rig, should the shut-off valves at the rear of the front trailer be open during inspection?

The correct approach is to ensure that the shut-off valves at the rear of the front trailer are open during inspection. Keeping these valves open allows for a proper check of the air supply and brake system in the entire setup, which is critical for safe operation. If the valves were closed, it could lead to insufficient air supply for braking, potentially compromising safety while operating the trailer combination.

During inspection, it's essential to verify that all components are functioning correctly to prevent any failures on the road. Open shut-off valves allow for a flow of air through the lines, enabling a thorough inspection of the brake systems and ensuring they are operational.

Ensuring the proper flow and operation of the braking systems in both trailers also helps maintain stability and control while driving. This is vital when inspecting a two-trailer configuration, as any malfunction in the system can have serious repercussions.