Early evening encounter at intersection near Arlington High School with object hovering obove interestion, then quickly disappearing.

Was driving to Arlington High School for a basketball game (therefore probably a Friday night).  It was still daylight (getting near dusk, so the date of Dec. is uncertain as it has been a long time). 
As I approached an interstection with Route 55 (?) from a rural road just east of the high school, I saw a very distinct object hovering at very low altitude above the intersection as I approached.  I stopped and had a visual sighting for several minutes (there was no other traffic on this back road I was on.)  I believe the object was traingular in shape, but it did have what I remember to be 3 blinking lights on its perimeter.  They were different colors.  
Then as the lights changed colors, the object quickly and silently took off in a westerly direction.
Witness indicates that the date of the incident is approximate.  PD