As a biker, I have noticed that many people do not realize that trails are often split into sections for pedestrians and bikers. Many people put others in danger by straying onto the wrong trail without warning, and causing accidents. What if there were electronic signs that warned of oncoming bikers or pedestrians so others could get out of the way in time. There is no "dominant race" on the trail, but there are some simple rules of ettiquete that could be helped along by this simple device. I suggest an led matrix and an infrared sensing system powered by a Raspberry Pi. Any suggestions?
