Most stop sign laws say something like:
The driver of any vehicle approaching a stop sign at the entrance to, or within, an intersection, shall stop at a limit line, if marked, otherwise before entering the crosswalk on the near side of the intersection. If there is no limit line or crosswalk, the driver shall stop at the entrance to the intersecting roadway or railroad grade crossing.
To be found guilty of this offense, in most states all the following conditions (legal elements) must be satisfied:
Here are the most successful defenses.
Most statutes say you must stop at the limit line, crosswalk, or entrance to the intersection. Practically, this means you must stop slightly before you reach this line. Some conscientious drivers, however, stop farther back from the white marker line or crosswalk. In these cases, an officer hiding behind a bush 50 feet down a side street might not be able to see whether the driver stopped or not.
To mount this defense, first request a copy of the officer's notes. Then go back to the scene of the ticket and take pictures from exactly where the officer was sitting. Especially if you can document a visual obstruction—and convincingly testify you did stop—this defense is often a winner. Of course, it's a big help if you can produce a passenger or other witnesses who will sign on to your version of the facts.
Here you concede that while you may have run the stop sign, it wasn't your fault. This can occur if the stop sign is hidden by storm-blown branches, twisted the wrong way by kids, or obscured for any of a variety of reasons. Called a "mistake-of-fact" defense by lawyers, what this amounts to is your claim that, given the information you had, you made a reasonable mistake and are therefore not guilty. But realize you have to prove your mistake was truly reasonable—it's never enough to say it was "a little hard to see the sign, Your Honor."
Pictures are worth a thousand words. Pictures taken from different angles or distances are more convincing than your testimony. For example, if a stop sign is hidden from view by overhanging branches until a few feet before the intersection, take pictures from inside your vehicle (with some one else driving) as the car approaches the sign. Snap one from a distance of 75 feet, and others from 50, 25, and ten feet away from the sign. (Label each photo with the exact distance from the sign.) In court, you may show your pictures to the judge and explain that they reveal the sign was obscured until it was too late to stop at the intersection.
To video or not to video. Lots of judges are hostile to videos. Most traffic-court courtrooms are not equipped with video players and monitors, and even if they are, judges may resent the time it takes to set up and watch a video. That said, portable video players have made it much easier to present your video in court, and so if you feel your case hinges on the evidence in your video, it may be worth the trouble. If you really feel you need to make your point with a very short video, contact the clerk well in advance to find out whether the judge will let you show it in court.
Ignorance is no excuse, even in a mistake-of-fact defense. It is not a mistake-of-fact defense to say you did not know it was illegal to do something illegal (roll through a stop sign, for example). You were taught the rules before you got your license, and you are expected to know them. A mistake-of-fact defense works only if you reasonably lacked a piece of factual and important information when you broke the traffic law. This would be the case if a traffic sign was missing or seriously obscured, but not if it was obvious and you just failed to see or abide by it.
Another possible mistake-of-fact defense exists if you are ticketed for blowing through a newly installed stop sign. No question, it is easy to miss a new sign on a familiar road. But this has a hope of working only if you can prove the sign really was recently installed and that you used the road frequently before the sign was installed. It will also help if you can introduce pictures into evidence showing the sign was also hard to see from a distance (just around a curve, for example).
Crosswalks and limit lines fade. If you are ticketed at a stop sign for stopping a little too far into an intersection, you may win if you show that the limit line or crosswalk was too faded to see clearly. Here again, a picture is truly better than a thousand words.