Suspect was tailgating in a speed limit zoned at 40 m/ph. I was behind another vehicle that was going 46 m/ph; the same speed I was going. The suspect then went into oncoming traffic and began to speed past me and the other vehicle. Suspect reached an estimated 60-70 m/ph in a 40 m/ph zone. Children were present; but thank god no child was crossing the street. Suspect continued to speed past until reaching the beginning of a school zone, where he turned into a high school parking lot. I followed the driver in and took a picture of license plate.