Operational for more than 50 years, T.Y. Lin International is a full-service infrastructure consulting firm. The firm specializes in the planning, design, construction engineering and inspection of transportation infrastructure. It maintains a staff of more than 1,000 engineers, professionals and planners. T.Y. Lin International offers program management services, as well as intelligent transportation systems. The firm serves airports, bridges, roadway systems, ports and marine, and rail and transit. It specializes in various types of aviation projects for domestic and international airports. The firm also has expertise in the areas of seismic analysis and retrofit design of bridge structures. T.Y. Lin International is headquartered in San Francisco.