Flying Saucer Road Signs

houston-oct-4- 004, originally uploaded by srinidhilv.

Houston, as all of us know is home to the NASA and this coastal city was the base for all the lunar missions and to this day this hosts one of the largest space museums worldwide. When I visited this city I noticed one thing special about the major landmarks here. All the road signs and intersections are shaped like a ring. In my imagination this looks like a transverse section of a spaceship or a flying saucer.
I may be wrong, but look at the top circle/ ring of this road sign and you will agree with me. If what I am thinking is right, then I think every city should enhance their appearance by placing their pride in full view of the world.