STV was initially contracted by the Southern California Regional Rail Authority to study the feasibility of developing commuter rail services into Los Angeles Union Passenger Terminal, which had been primarily used as a hub for Amtrak intercity passenger rail service. From there, the firm served as the general engineering consultant for Metrolink, Southern California’s first foray into commuter rail service. STV was responsible for program management, planning, engineering design, and construction management for various key assignments throughout the system’s development. This included the modification of nearly 230 track-miles of existing right-of-way; the addition of second main tracks, sidings and line extensions; and work involving new maintenance facilities, storage yards, signals and communication systems, and local permitting.

With more than 50 stations throughout the entire system, STV also prepared the commuter station design manual for Metrolink. The firm initially designed eight stations and reviewed the plans of the local government’s architect for a number of other commuter rail stations. 

Metrolink is now one of the busiest commuter rail systems in the United States, serving Los Angeles, Orange, Riverside, San Bernardino and Ventura counties in Southern California.