Capital Rail Constructors (CRC), a joint venture governed by Clark Construction Group and Kiewit, has reached ‘substantial’ completion of construction on the second phase of the Metrorail Silver Line extension project.

Under the project, which is being managed by the Metropolitan Washington Airports Authority (MWAA), CRC was responsible for design-build works.

The milestone has paved the way to enable the commencement of operational readiness testing, which will showcase the project’s functionality.

The project involves the extension of the region’s Metrorail public transit system, which is operated by Washington Metropolitan Area Transit Authority (WMATA), to Dulles International Airport and beyond.

CRC project director Keith Couch said: “After successful Phase 1 and Phase 2 tie-in testing at Wiehle Avenue, MWAA has approved substantial completion of the Package A Silver Line Phase 2 project. The project will now move into Operational Readiness Testing, which will be completed by MWAA and WMATA.”

The Package A Silver Line Phase 2 project will include 18.5km of new track, stretching from the Wiehle-Reston East Station to a terminus in Loudoun County, along with six new Metrorail stations.

It also encompasses the construction of a 90a rail maintenance yard at Dulles International Airport.

Under a separate contract, the construction of the yard, which is being executed by Hensel Phelps, is also nearing completion.

After the completion of operational readiness testing, MWAA will pass on the project to WMATA to make the final preparations required to initiate revenue service.

In 2014, Phase 1 of the Silver Line opened, covering Metrorail service from East Falls Church to the eastern edge of Reston.

The Silver Line aims to minimise traffic congestion by offering alternative routes and better commuting times.