Like most people, Christina Downs was not particularly pleased when she received a ticket for going 48 MPH in a 25 MPH zone. Like some people, Downs contested her ticket. Unlike most people, Downs continued to contest her ticket, all the way up to the Maine Supreme Court.

Not surprisingly, the Maine Supreme Court ruled against Down, affirming the conviction handed down by the lower courts. The text of their decision can be found here. Decision No. Mem 08-166, Docket No. Yor-08-121. In my experience, you are guilty until proven innocent in traffic court, and the burden of proving innocence, in practice, is virtually insurmountable. A far better approach is to plead guilty and ask the court for lenience. As this case demonstrates again, actually proving innocence in a traffic court case is a very long, slippery slope to climb.

But far more interesting from a legal perspective is how the rules of evidence and discovery played out in this case. Down appealed to the Maine Supreme Judicial Court under the theory that the court erred in not requiring proof of engineering and traffic studies to support the 25 MPH speed limit. The court held that this was not a reversible error, and that, absent any proof, posted speed limits are sufficient to establish 1) the speed limit and 2) that the speed limit was determined in accordance with law. The issue of course is how do you prove number 2? The most logical approach is Down’s approach - request and review all of the documents showing how the State, County, or Town arrived at the speed limit and then show that the evidence does not supported the speed limit. The only other option would be to hire one’s own expert in speed limit determination and offer a differing account. Good luck finding such an expert, let alone one that is actually willing to testify on your behalf.

There is also the general principle that you should be entitled to all available evidence that may pertain to your case. This is called the “Discovery” phase of any trial - civil or criminal - and is the cornerstone of the American legal system’s validity. The opinion doesn’t reflect whether the evidence was specifically denied, or whether there simply was no evidence requested. What it says actually dismisses the issue entirely, as the Court says that it is not necessary at all.

Which gets us back to the main question: how do you prove question 2? The Court’s answer: you DON’T NEED to prove question 2. It is presumed to be valid. While skeptics of speed limits might cringe at this conclusion, as a matter of law I cannot find much fault with it. Most laws on the books are presumed valid regardless of how the legislating authority arrived at the specifics of the law.

So what is the take away point? In Maine, speed limits are valid unless you have proof to the contrary, and the burden is on you to produce that evidence. My guess is other states would rule the same way.