HNTB knows the ABCs of A/E. The company is a pure design firm, which generates most of its revenues from architecture, engineering, or environmental-design operations. HNTB specializes in transportation infrastructure projects and government contracts. The firm is best-known for its highway and transit system design (its portfolio includes the New Jersey Turnpike), as well as airports (Chicago's Midway) and sports arenas (Sports Authority Field at Mile High in Denver). The company operates some 60 locations across the US. The employee-owned HNTB (its name once stood for Howard Needles Tammen & Bergendoff) traces its roots to 1887, when it was a consulting practice.