While driving in a dark street in Nevada (I was going from Wells to Ely at night time) I saw a light appearing behind me in the distance. At first I thought it was a car, then we saw (other two people were in the car with me at that moment) the light coming closer to us and then moving from the street to the field at its left in a horizontal way. The light was still pointing at us but it was moving right to left, like if it wasn't touching the street. After a bit we saw a car driving to the opposite direction, and when the car reached the light (that at that moment it looked like it was back on the street) both turned off. After few seconds we saw the light appearing again. Few minutes later a big truck got between us and the light and few minutes later the truck disappeared and the light was back again behind us. It took off a bit (like if it was flying) and then it came back on the street. Sometimes it was changing shape and after disappearing for a longer time we saw three lights on the field at our left. Then two lights disappeared and the one that was still on came back on the street like if it was fluctuating few feet from the street (from left to right). Few other cars came from the opposite direction and some of them were disappearing as soon as they were close to that light while some of them were just passing by it. The street was perfectly straight, no bumps, no turns. All of the sudden it got really close to us and when another car, coming from another direction, passed us by, the light turned off and the object got hit by the other car's lights and I could see a conical disk behind us. Dark violet/black color, as large as the the lane of the street. Once we started approaching Ely, the light disappeared for good. We made a video but it's too dark to see anything.