Alstom and Ansaldo-STS supplied signalling for Washington's Silver Line

The Silver Line's train control/signaling (Automatic Train Control) systems came from two different European suppliers: Alstom (France) supplied/was responsible for the Phase 1 ATC system (through Wiehle-Reston East) and, per MWAA/WMATA project records, had to verify and sign off on the integration/compatibility work at the interface with Phase 2; Ansaldo-STS (Italy, now branded Hitachi Rail STS following Hitachi's acquisition) was the ATC/signaling supplier for Phase 2. The mismatch between the two systems caused significant delays at the Wiehle tie-in, as documented in reporting and the WMATA OIG report.

Phase 2 of the Washington Metro Silver Line (11.5-mile extension to Dulles International Airport, six new stations, approx. USD 3 billion) opened on November 15, 2022; the main design-build contractor for construction/systems was the Capital Rail Constructors joint venture (Clark Construction/Kiewit, US/Canada). However, the train control technology came from two European suppliers: Alstom (France) for Phase 1 and Ansaldo-STS/Hitachi Rail STS (Italy) for Phase 2; per WTOP reporting based on MWAA/WMATA documents, Alstom had to verify and sign off on compatibility/integration at the Wiehle-Reston East interface, causing years of delay.