Close encounter on the highway with a hovering craft/bright lights (white, red and orange).

In January 1990 I was a student at the University of Wisconsin in Platteville. I held a night job in Dubuque Iowa, which is about a 30-minute drive from Platteville through mostly rolling hills and farmland.
One night at about 1am, during my drive to Platteville from Dubuque, I noticed some lights in the distance going back and forth over an open field. I wondered why a farmer would have his equipment out at that hour, especially in January when there is so much snow on the ground. I was puzzled but I didn’t put much thought into it.
As I drove down the hills, I would lose sight of the lights but as I came back up I could see them again. There were three colors: white, red and dark yellow/orange. The lights continued to pass back and forth along the countryside. I drove down another hill and lost sight of whatever it was. I was almost back to the school campus, right on the main highway going into the small town of Platteville.
Suddenly, the lights were right in the middle of the road, right in front of me!  Not more than 40 feet!  It was hovering over the road and the lights were rotating. I was absolutely terrified! Plus, it was difficult to see. I had to make a choice, either keep driving straight, which would take me directly under it, or make a fast turn onto a winding back road. In a split second, I decided to turn off onto the back road. I was consumed with fear. I just wanted to get away from the lights. I barely used my brakes as I made that turn. I’m not sure how I didn’t lose control of my car.
I kept looking in my rear view mirror to see if the lights were still there. Nothing. I calmed myself down a little and tried to rationalize that whatever I saw was sure to still be on the highway. It must have been a semi or emergency vehicles or something! My heart was still racing, but at the end of the road, instead of making a left to go back to the campus, I decided to make a right turn back around to the highway. There was nothing. No lights, no semi, no emergency vehicles, no farm equipment. Nothing! Surely, if the lights I saw could be attributed to any of these things, I would have still been able to see it from the highway.
I will never know exactly what I saw that night. All I know for sure is that I have never felt terror like I did when I had my close encounter.
Date is January 1990 is approximate.  PD