When centering the side mirror adjustment, what should be visible on the inside edge of plane mirrors?

When centering the side mirror adjustment, what should be visible on the inside edge of plane mirrors?

• A. Part of the trailer.
• B. The road ahead.
• C. The trailer body.
• D. Other vehicles.

Answer: (C)

When you set up flat (plane) mirrors, the goal is to have a clear reference to your own vehicle so you can judge where the trailer is relative to the cab and to other traffic. The inside edge of a plane mirror should show part of the trailer body. This gives you a stable cue about the trailer’s position and helps you avoid misjudging distances or lane placement as you steer or maneuver. Seeing the road ahead in the inside edge isn’t the purpose of this mirror section, and while you will still monitor other vehicles in the wider field, the primary reference for proper adjustment is the trailer body visible at the inner edge.

When you set up flat (plane) mirrors, the goal is to have a clear reference to your own vehicle so you can judge where the trailer is relative to the cab and to other traffic. The inside edge of a plane mirror should show part of the trailer body. This gives you a stable cue about the trailer’s position and helps you avoid misjudging distances or lane placement as you steer or maneuver.

Seeing the road ahead in the inside edge isn’t the purpose of this mirror section, and while you will still monitor other vehicles in the wider field, the primary reference for proper adjustment is the trailer body visible at the inner edge.