Actually, it's the Holy Riders, an evangelical biker gang lead by a man that is obviously an avatar of some archetype, but which one is unclear. They're removing the signs to prevent "traffic with the dead and demonic". Some say it appears to be working, as demon activity has been lower around the route, but rumor has it that the gang is doing more than just removing road-signs. In fact, all evidence points to something very wrong going on. Or, at least, involving a component which is very wrong. Whether the overall effect is worth it, time and investigation will tell.