Costain Group PLC provides infrastructure solutions for the transportation, energy, water, and defense sectors in the United Kingdom. It operates in two segments: Transportation and Natural Resources. The company serves the road, rail, and integrated transport markets, as well as the water, energy, defense, and nuclear energy markets. Its services include engineering, construction, maintenance, renewals, advisory, design, and consulting. Costain Group PLC was founded in 1865 and is headquartered in London, the United Kingdom.