This was witnessed by myself while en route to Minot ND, driving my personal vehicle. I had previously been assigned to Minot AFB in 1985, and was a Capt on a B-52 crew when I separated in 1990. I was returning to visit friends and family in 1992. What I witnessed was in fairly under-populated area on a stretch of HWY 2/52 that had about an 8 to 10 mile visual shot of the horizon to the west due to terrain. I had not seen oncoming or trailing traffic in sometime. The road is a 2 lane blacktop running parallel to a set of active railroad tracks. I noticed an extremely brilliant light cresting the horizon. My immediate thought was oncoming train. I took notice shortly after my initial sighting and thought it was moving at and unusually high speed. Shortly after that I could discern the horizon line was below it. I decided to stop my vehicle and try to determine what this was. I pulled to the shoulder of the road and exited my car. I couldn't believe the rate of speed this object was moving. The single bright light was the only thing I could see. My estimates of his speed are 600 to 800 KTS. I felt the need to move behind my vehicle. The tracks were approx 100 yds from the road. It went by me with no change in altitude or direction. The vehicle stayed directly over the rail tracks during my observation. As it passed, the bright light was no longer visible, but multiple round multi colored random pulsing light came into view. There may have been 5 or 6 of these lights pulsating different colors. This looked to be the propulsion of the craft. The most unexplained part of my experience was the fact that no sound was ever made. I watched until it disappeared over the east horizon. I was shocked. I completed my drive to Minot and to this day am trying to understand what I saw. I finished my flying career as an 747 instructor with Delta Airlines and retired in 2012. In my military and civilian flying careers, I have not seen anything else that I could not explain. This event I cannot. I was curious if anyone else saw this or anything similar.