The Crystal City/Potomac Yard corridor runs north-south between the Pentagon and Pentagon City in Arlington County and Braddock Road Metrorail Station in the City of Alexandria. The map at left shows the project location in a broader, regional context; and the map at right shows the system alignment divided into six segments. As indicated in the legend below, the purple lines represent portions of the alignment in which transit vehicles will operate in mixed traffic, while the orange lines represent portions in which transit vehicles will operate in an exclusive right-of-way. In April 2007, the FTA approved the environmental review of the planned improvements in Segments D and E in Crystal City and Potomac Yard.