What is the basic location reference point used in highway construction?

The centerline serves as the fundamental reference point in highway construction due to its role in defining the alignment and layout of the roadway. It acts as a central axis from which measurements and distances are established, ensuring that the road is constructed symmetrically and within specified tolerances. By using the centerline, construction teams can accurately position lanes, shoulders, and other features, facilitating proper drainage and roadway safety.

This reference point is vital because it allows for consistent application of design standards and helps avoid potential conflicts with existing infrastructure. By starting measurements from the centerline, it simplifies the process of establishing horizontal and vertical alignments, which are crucial for the overall geometry of the highway. Additionally, using the centerline helps in phase planning during construction, as well as in future maintenance and modifications of the roadway.