I would hazard a guess that what you observed was the traffic lined up for a standard PHL arrival. You most probably observed a string of landing and/or collision avoidance lights extending into the distance. Relative speeds of other vehicles, especially aircraft, are very difficult to estimate from a moving automobile.
NAS Willow Grove closed in September of this year and all of its air assets have been transferred to Joint Base McGuire-Dix-Lakehurst.