The term centerline is commonly seen in the [:to reach:to-reach] part of a ["datasheet"]. It means an imaginary line along the center of a road. The idea is that the width of the road will be more likely to change than the position of the center of the road with time, and and that the position of the edge of a road would possibly be more difficult to determine than the position of the center of the road.

The concept of a centerline must be used with caution when a road has been significantly widened, especially if more lanes have been added.