I was driving to work at 8:30 in the morning, going South on Hwy. 259, heading towards Longview, TX. First noticed a bright light in sky. Thought it was a plane with light but very unusual. But lights got bigger & unnaturally bright. Observed this for about 8-9 minutes. I looked around at traffic to see if anyone else had spotted it, but didn't see anyone looking at it. All of a sudden, light disappeared & in it's place was a flying saucer disc shape, kind of grey metallic, with a large fin on top. Slanted & concave on right side, flat on top, & a half circle on back. At the time I couldn't believe what I was seeing. Blinked my eyes for a better look & it had completely disappeared. I scoured the sky for about 10 minutes & there was nothing.