Official definition
This subsector comprises establishments whose primary activity is the construction of entire engineering projects (e.g., highways and dams), and specialty trade contractors, whose primary activity is the production of a specific component for such projects. Establishments may produce new construction, or undertake additions, alterations, or maintenance and repairs to existing structures and works. Establishments in this subsector are classified based on the types of structures that they construct. Specialty trade contractors in this subsector generally provide specialized services of a type related to heavy and civil engineering construction projects and not normally performed on buildings or building related projects. For example, specialized equipment is needed to paint lines on highways. This equipment is not normally used in building applications so the activity is classified in this subsector. Traffic signal installation, while specific to highways, uses much of the same skills and equipment that are needed for electrical work in building projects and is therefore classified in subsector 238 Specialty trade contractors. Construction projects involving water resources (e.g., dredging and land drainage) and projects involving open space improvement (e.g., parks and trails) are included in this subsector. Establishments whose primary activity is the subdivision of land into individual building lots usually perform various additional site-improvement activities (e.g., road building and utility line installation) and are included in this subsector.