It will carry out the US$697m (£540m) electrification of the 84km Caltrain rail corridor between San Francisco and San Jose, in preparation for the future operation of high-speed trains.
The Peninsula Corridor Joint Powers Board awarded the contract to Balfour Beatty as part of the Caltrain Peninsula Corridor Electrification Project. The electrification will bring cleaner, high-performance electric vehicles to Caltrain's fleet, allowing for a more frequent service.
Reliability and capacity of the rail service, which operates through 17 US cities across San Francisco, San Mateo and Santa Clara counties, will also be enhanced.
Balfour Beatty group chief executive Leo Quinn said: "Our extensive experience in managing complex rail projects leaves us well qualified to deliver this significant scheme. Caltrain builds on the back of the recent successful delivery of our part in the multi-billion dollar Eagle P3 Commuter Rail network in Denver, Colorado.
"We are pleased our unique capability has been recognised with this award which contributes to our strategy to increase our design-build rail market share across the US."
Balfour Beatty Infrastructure will design and build a 25kV AC overhead catenary system to serve as the power source for the new high-speed trains. The work includes construction of two traction power substations, one switching substation and seven paralleling substations. The company will also replace signal systems and earth existing facilities as part of the process to electrify the existing corridor.
The project is due to start this autumn with completion expected in spring 2020. A workforce of over 300 will be employed at project peak which will include 50 apprentice opportunities.