VRE Train P307 had detrained all of its passengers at this point and was leaving the passenger station at Fredericksburg, enroute to the VRE maintenance facility several miles south at Olive.
A northbound commuter train off the "Manassas Line" makes an early morning stop at Crystal City during its final leg into Washington DC's Union Station. VRE V10 started life as B&O 4016 (GP40).