STC provided engineering and construction support services for the new Arrow rail line in San Bernardino/Redlands, a $300 million extension of the Metrolink line along nine miles of existing right-of-way. This complex rail system involved multiple stakeholders, including Metrolink, Omnitrans, Caltrans, CPUC, and local cities, each with unique needs and systems requiring seamless integration. STC delivered design and construction services in traffic engineering, customer information systems (CIS), and communication systems.

To transition the project from the environmental phase through final design and into construction, STC prepared several key documents, including the Concept of Operations (ConOps) for various technology systems, Basis of Design for transportation systems, operational impact analysis of grade crossing improvements, alternatives analysis of train operations and impacts, and the Traffic Management Plan for construction.

Following construction, STC provided traffic signal cutover support services, agency testing support services, monitoring of traffic signal operations, and communications system support.