Multiple pulsating lights trailing each

I was sitting at a gas station, eating and looking south on I-75 South, and I saw a pulsating white light in the distance, moving in a horizontal direction from east to west. After that, two minutes later, another light came, moving at a steady pace. Two minutes later, the same lights came back from the west and started heading east. Estimated altitude was about 16,000 feet and about 15 miles out with no trees or obstructions. I ruled out as being an aircraft because there are no active high altitude airways that go from west to east in this area only south.