Setting aside minor traffic infringements, intent is a very basic part of criminal law.

As a counter-example, what if you hit someone with your car? Do you think it should matter if evidence exists that it was an accident or if there is evidence that you hit the person purposefully?

Every time I've been pulled over, the officer asks "do you know why I stopped you?" If I claim I honestly don't know, there's a better chance that the fine may be reduced. Or going in the other direction, 10mph over while driving might garner a warning, while 10mph over with another car next to you doing the same speed would get your car impounded for street racing.