A person may drive on public or private property to avoid a traffic sign or signal when

In an emergency situation you may do this. This also depends on how you define public property. By this do you mean next to a sidewalk, driveway, or parking lot. Or are you referring to places like a yard or front lawn? Most of the time when you do stop this is usually do to a police siren or ambulance or fire truck that has the lights on. In this situation you must park to you right and off the road to clear a path. But do so with out damaging someones property. As you should already pay attention to the road at all time.