There is a section of the GW Parkway that is directly across (i.e. west) of the Potomac River from the Lincoln Memorial. It the wreck was there, almost at the entrance to Arlington National Cemetery, one is talking about 2-300 yards west. I’ve driven that small stretch of GWP a couple of hundred times during the 30 years I was in DC.
However, re my previous post, I’m unsure of where along the GWP that would be 5 miles away that would give that image. I’m wondering if the original location report is wrong.