This morning, at 9:45AM on Thursday, May 14, 2015, I was driving on I270 from Hyattstown, MD toward Germantown, MD, when I saw at about 20 degrees above my horizon, and ahead of me in the sky, 3 objects. They were flying in a straight line, left to right across my direction of travel, and consisted of two silver cylindrical objects that I would guess were about the size of railroad tank cars but taller and maybe longer, and were ahead of a third object that was black, and square or rectangular in shape, and as large as the cylinders. I saw no windows on any of the objects, nor any means of propulsion - no wings or propellers - and no discernible tail features. There was no sign of any smoke or other exhaust features. I was in heavy morning rush hour traffic, in the center lane, and could not pull over to either side to stop for a better view. They were moving relatively slowly, and stayed in view for about 40 seconds before I drove past the point where they were off my right side and out of my sight. If they stayed on that course, they would have passed over the Germantown area. I don't know for sure what they were, and, unless we have technology that I am not aware of, I seriously doubt that they were made by man - homo sapiens. All of my life, I have believed that we are not alone. Now, unless this can be explained away, I am very sure we are NOT alone!