I was driving home from work,traveling south on I 55 , I exited on route 126,as I came to the end of the exit ramp I saw and extremely large triangular shape hovering over a small retention pond on my left. I pulled over and stopped to get a better look, rolled down my window and heard no noise at all from this aircraft. Since I could not hear any sound coming from it I shut my truck off and got out and stood on the side off the road. I observed this aircraft for several minutes and during that time I was able to get a good sense of the altitude,size and height and shape of this aircraft. This craft hovered about 75 feet above the pond the total length was about 600 feet and was 40 to 60 feet tall. The back of the aircraft had 4 rows of lights which looked like windows and they were emitting white and bluish lights, all of these windows were not lit brightly but did emit light. After observing this and not seeing it move I got back into my truck and began to pull away. As soon as I started moving the aircraft began moving in the same direction I was and remained on my left side and matched my speed. I would stop and this aircraft would stop, this craft remained with me even when I was stopped for a red light on 126 and route 59. I continued on 126, made a right turn and it made a right with me. I than made a left turn on Indian boundary road. The speed limit was 25 mph on this road because it is residential. It remained with me and still matched my speed. My window was down all of this time and I still heard no noise from it. When came out of the residential area it turns into a 2 lane road with corn and soy bean fields on both sides. I than accelerated to over 90mphs and than stopped at county line road and Indian boundary, I got back out of the truck and observed it for a few minutes, it also had come to a stop and was hoovering again, and than it took off to the west at a very high speed and went over the horizon within a few seconds. It never made a sound even when it accelerated.