If you live in a city with red light cameras that snap pictures when you accidentally sneak through a red light then chances are you've received a ticket with your picture in the mail before. Hacker Dave was so annoyed with these tickets he decided to rig up a GPS to alert him when he was near a right light camera.
Using a GPS receiver, an OLED display, a database of red light cameras and an Atmega with a Arduino bootloader, Dave created a simple system that alerts him when he's near a red light camera. It's not perfect and still won't stop you from accidentally running a red light, but it might be enough to make you more conscious of your driving when you know red light cameras are in the area. Hit up the link below for a full walkthrough and the source code to make this project for yourself.