Production of road motor vehicles; Manufacture of special equipment; Highway management and maintenance; Subgrade and pavement maintenance operations; Construction labor subcontracting. General items: Research and development of mechanical equipment; Manufacture of specialized equipment (excluding licensed specialized equipment); Manufacture of construction engineering machinery; Manufacture of new building materials (excluding hazardous chemicals); Municipal facility management; Engineering management services; Information system integration services; General equipment repair; Leasing of construction engineering machinery and equipment; Leasing of mechanical equipment; Technical services, technology development, technical consultation, technical exchange, technology transfer, technology promotion; Automobile sales; Sales of construction engineering machinery; Sales of building materials; Sales of mechanical parts and components; Sales of non-metallic mineral products; Manufacture of specialized chemical products (excluding hazardous chemicals).