Sure it's easy to fake, but you are under oath. You can stand up there all day and say that, to the best of your knowledge you were not speeding and not perjure

Sure it's easy to fake, but you are under oath. You can stand up there all day and say that, to the best of your knowledge you were not speeding and not perjure yourself. If you get up there with forged documents and get caught, that's something else entirely. So, they are not iron-clad evidence, but they should be pretty good.