chaussée

Chaussée is a French term used in civil engineering and road transport to designate the portion of a public road that is intended for vehicular traffic. In many francophone contexts it corresponds to the carriageway in English. The chaussée is the surface of the road that carries vehicles and is part of the wider road structure, and it is distinct from adjacent elements such as sidewalks (trottoirs), shoulders, and verges.

Etymology: The word derives from the French term chaussée, related to chaussure (shoe) and to the idea of a path worn smooth by use. The sense reflects the long-standing notion of a travelled surface shaped by wheel and foot traffic.

Structure and materials: In typical road construction, the chaussée comprises several layers: a foundation or subgrade (fond de forme), a base layer and base course (couches de base or couche d’assise), and the wearing surface (revêtement) made of asphalt concrete or Portland cement concrete. A drainage system beneath and alongside the chaussée helps maintain performance and longevity. The wearing surface is the part most directly exposed to traffic and weather, while the underlying layers provide structural support and moisture control.

Variants and usage: The term is used in planning and maintenance to distinguish the traffic surface from other street components. In French road design, roads may be described as “à chaussée unique” (single-carriageway) or “à chaussées séparées” (divided carriageways), indicating whether opposing traffic shares a single carriageway or uses separate carriageways. The word also appears in legal and administrative contexts to define responsibilities for pavement upkeep and safety.