What is the correct position to line up the tractor when preparing to back under the semi trailer?

The correct position to line up the tractor when preparing to back under the semi trailer is directly in front of the trailer. This positioning allows for the most straightforward alignment when coupling the tractor to the trailer. Being directly in front facilitates a clear path for the kingpin to connect with the fifth wheel, ensuring that the cab and trailer can engage smoothly without misalignment.

When positioned directly in front, the driver has better visibility and control over the movements necessary to back under the trailer accurately. This alignment minimizes the risk of hitting the trailer, which can lead to damage and challenges in coupling. Other positions, such as angling left or right, could complicate the backing process and increase the likelihood of errors. Additionally, staying several feet away from the trailer may create challenges in navigating close enough for the connection to be made efficiently. Thus, being directly in front is the most effective approach for successful coupling.