noun
carriageway marking; lane marker; compartment line; division line
Technical term used in road engineering and traffic management. Refers to painted lines on roads that separate lanes, parking spaces, or other areas.
高速道路の区画線は、夜間でも見やすいように反射材が使われている。
The lane markers on expressways use reflective material so they are easy to see even at night.
駐車場の区画線が消えかかっているので、引き直す必要がある。
The parking lot's compartment lines are fading, so they need to be repainted.
車線 means a traffic lane itself, whereas 区画線 is the painted line that marks the boundary of such a lane.
Compound of 区画 (くかく, 'division, section') and 線 (せん, 'line'). The reading くがせん reflects rendaku voicing of かく to がく.