Walkways act as catwalks for engineers to move quicker around their facilities.
This one in particular allows you to go 2m up or down.
Walkways can only be attached to foundations or other walkways, and are measured 4m in either direction, which is quarter of foundation. They have barriers to avoid accidental fall, unlike foundations. Therefore, they are a great way for secured move-around.
Due to their low cost, they are very useful for creating bridges that span large gaps.