I was going north on I45 around 1:30AM CST May 29, 2011. I was in the right hand lane, there was an area of grass to my right then trees. To my left was the other traffic lane, a grass covered median, then the traffic lanes for southern bound traffic. Traffic was very light, no vehicles very close to me. All of a sudden there was a very bright flashing light that seemed to be coming from above my car. I leaned forward and looked up and out the windshield. There was a small black circular object about 15 feet above my car, it had matched my speed (around 70 mph) and was flashing about once a second. There were no other lights, except the flashing one, and there was no noise. The object stayed just in front of, and above, my car for three or four minutes then slowed down and went to the truck behind me. I have checked the news in that area (north of Huntsville, a few miles south of Madisonville) but haven't seen any other reports of the sighting.