23 mile extension of existing 106 mile metrorail system - Dulles Corridor Projet,USA
 

Dulles Corridor Metrorail Extension Project, also known as the Silver Line. Recently project has been undertaken to increase the capacity of the existing metro system and extend its services to new areas.It's extension is expected to give service for approximately 85,700 passengers a day by 2030.Wish to see the project complete as early as possible.
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Good to see. Although it was some time ago, getting from Dulles into Washington DC was a nightmare.