Colas SA constructs and maintains transport infrastructure worldwide. It operates through three segments: Roads, Construction materials, and Railways. The company constructs and maintains roads and highways; and works on airfield runways and aprons, seaports, industrial sites, logistics and commercial premises, street construction and urban development, reserved-lane public transport, recreational amenities, environmental protection, etc. It also engages in the renovation, demolition, and deconstruction of buildings; and constructs small-scale civil engineering and drainage projects. In addition, the company produces and recycles construction materials, such as aggregates, emulsions and binders, asphalt mixes, ready-mix concrete, and bitumen. Further, it designs and engineers large projects; constructs, renews, and maintains rail networks, such as high-speed and conventional train lines, subways, and tramways; lays and maintains tracks, electrification, signaling/telecommunications, safety systems, ventilation, and fire detection/protection, as well as specific projects comprising bridge cranes, special branch lines, and repair of railway tunnels. Additionally, the company lays and maintains pipes and pipelines for the transport of water and energy, including the construction of turnkey gas compression stations, small-scale civil engineering works, and industrial services. It also engages in the manufacture, installation, and maintenance of road safety and signaling equipment; traffic management activities; and distribution of bitumen. The company was founded in 1929 and is headquartered in Paris, France. Colas SA operates as a subsidiary of Bouygues SA.