a T shaped cluster of blue/white lights hovering over I93

I was driving south on I93 and, shortly after Tilton, I saw what looked like white-blue lights hovering over the highway — higher than any building or structure, but way below planes overhead. There were no blinking lights, and no red/blue lights, as distinguish planes.
I kept an eye on the lights as I drove south and after a few minutes (meaning a few miles of road) I passed under them, with them still evidently stationary. The lights appeared to be in clusters of two, in a T formation; I could not tell, against the night sky, if there was anything between or among them, but it seemed like there was the dark outline of a craft between the lights.
As I drove south, I kept the lights in my rear view mirror, and they didn’t seem to move until I had driven another 5+ minutes/miles and the road had turned. I was unable to find a place to pull over to take a photo or video.
I asked my friend who is an ATC and he said there was nothing on radar in that area. However, a friend who lives nearby said that Sikorsky helicopters had been spotted in the area earlier circling (he had taken photos). Whatever I saw I am highly confident was not the running lights of a helicopter based on both lights and shape of craft.
No idea what it was.