WMATA extends the Silver Line 11.5 miles west from the Wiehle-Reston East Station, through Washington Dulles International Airport and into Loudoun County, Virginia.  

Bison Rail Systems was hired to provide signal system testing oversight and the following activities: 

• Supervision of signal system installation 

• Track Circuit Testing 

• Support technical issues during pre-testing 

• Microprocessor Testing Support 

• Cutover Support