I was driving west on the I-10 bound for Los Angeles CA coming from Litchfield Park AZ. I notice a bright group of flashing/rotating lights coming from the southwest in the direction on the highway. My first thought was I am looking at a helicopter approching. but at second glance the motionwas all wrong for a copter. It hovered then had a short burst of acceleration the hovered the a very fast acceleration covering what I estimated to be about 5 miles in a matter of seconds. I am still thinking "this must be a chopper !" the craft the in a final burst of speed crosses the highway in front of me, I estimate it is about 150 to 200 feet high and its huge! maybe 200 feet across, I can see 2 very bright lights at the ends of a long fairly thin dark structure, as the craft banks to the east it pauses in its turn and tilts slightly and hovers for just a second or two. at this point I can see three lights at the edges of a very large dark structure with a multitude of multi color chasing lights stemming from its center to the lights at its points, as it makes a very tight turn to the right. There is NO sound at all ! as it turns the 3 main lights turn to a dim red in color, I can see it is triangle shaped, equal sides. As the craft passes over my truck it seemed to be turning on a central axis as it banks (kind of like a frisbee toy) at this point I have no idea what this thing is! It heads back southeast and I can see that the sides of the triangle are a bit concave and have a "airfoil" shape giving it the apparance of a 3 point boomerang ( a bit fat in the center) I can clearly make out a 4 centrally located light orangeish in color as it pulls away I can clearly see it had rows of lights on the edges of the body. The body was black but had a slight "shimmer" to it. I was driving about 65 or 70 miles per hour and this thing completes its turn before my truck can pass under it. As it clears the highway it pulls out at a very high rate of speedand is heading toward the southeast in the direction of what I assumed to be the Goodyear Muni Airport (saw the blue runway lights in the distance) and in a second or two it was half way to the horizon. Then it was just a speck of light (still flashing) on the horizon. I was amazed, still no quite sure what I had just seen, then a bit frighten! the totally excited, the images kept replaying in my head! the whole thing had a serreal feel to it. I have never seen anything remotely like this. I kept doubting what I saw trying to come up with a logical explanation for what had just occured. I could not think of anything else to do so I posted it on my facebook page while I was driving. Then I called my wife and told her. I had to stop at the very next rest stop to compose myself. I kept watching the sky for most of the remainder of my drive to Los Angeles. I kept thinking "it should have made some kind of a sound!" I have always wanted to see proof of these type of aircraft, now that I have seen this one I my not so sure I would like to confront another !