centerlinjer

Centerlinjer, or centerlines, are markings on road surfaces that mark the approximate center of a travel lane or roadway. They help separate opposing traffic streams and guide vehicles to stay within their lanes. On two-lane roads, the centerline typically distinguishes directions; on multi-lane roads, centerlines help organize lane use and alignment. The markings also serve as a reference point for turning and overtaking decisions.

Line types and meanings vary by jurisdiction. A dashed or broken centerline indicates that crossing is allowed when traffic and road conditions permit; a solid centerline means crossing is prohibited. A double solid centerline indicates overtaking is not allowed in either direction, while configurations with a solid line on one side and a dashed line on the other may permit passing only from one direction. Color schemes also vary: in many regions, white centerlines separate lanes in the same direction, while yellow centerlines separate opposing directions, particularly on two-way roads. Temporary centerlines in work zones are often yellow or orange.

Other features and uses: Physical medians or raised islands can replace painted centerlines to separate traffic more definitively. In cartography and GIS, a centerline is the reference axis of a street or road used for network modeling and map accuracy.

Standards and maintenance: Road authorities specify line width, segment length, spacing, and reflectivity to ensure visibility under day, night, and adverse weather. Regular maintenance keeps centerlines clear of wear, debris, and snow, contributing to safety and traffic efficiency.