There are more than 200,000 Railroad Crossings in the USA. Lowbed semi-trailers and car haulers have a much lower clearance than regular trucks, and are notorious for getting stuck in rail crossings and speed bumps. Every crossing in the USA has a little blue sign with a phone number and a crossing number on it. When a vehicle get stuck on the crossing, anyone can call the number which is the railroad dispatch. They can radio to stop any trains nearby immediately.