Returning to Missouri from Godfrey IL, ,Driving south on Hwy 270 on a stretch of the highway that airplanes fly over before landing at St. Louis Lambert Field. It was approx 6:30pm CST, clear sky, twilight-blue color sky. I have seen planes in this area before when they are approaching Lambert Field to land. This occurance I saw many BRIGHT white lights to my right and looked to watch the plane fly over the highway. I saw approx 5 bright white lights that I assumed were the lights the planes use when landing. I realize that I did not see an airplane shape,nor did I see any other color lights that planes usually have. I just saw a group of bright lights. As we traveled south on the highway, I followed the lights to watch the airplane descending. As I was watching, the lights/plane(?), in the blink of an eye I saw what became only 3 bright white, round lights that formed a triangle shape, like an elongated triagle, 2 lights closer and one like at the point. I could see blue sky all around, no solid triangular shape, just the lights. It was pointed a little more north than it had been. I did a doubletake because this surprised me so much. Later, while thinking about what I saw, I realized that there had been no sound! Landing planes make a loud noise you can hear when they are flying here. A few years ago, there was a sighting of a black triangular UFO in the Alton Il/St. Louis MO Areas. This had even been on national news. There was no solid shape to see, but the lights I saw formed into the same type triangular shape. As I saw this, I thought whaaaaaaat am I seeing? I watched the lights as we drove further down the highway until it was out of my sight. All of this probably only took 2 or 3 minutes. I still wonder what I saw. I honestly don't think it was a plane. I saw 3 bright white round lights in a triangular shape. There was nothing in the news here if anyone elsesaw it. (My husband was driving the car but didn't see this.)