What is gauge distance?

Gauge distance is a measure of the distance between two parallel railroad tracks. It is typically measured from the center of one rail to the center of the other rail, and varies by country and region. The standard gauge distance in the United States is 4 feet 8.5 inches, while in many European countries it is 1.435 meters. Gauge distance is important for ensuring that trains can safely and efficiently travel along the tracks without colliding or derailing. It also determines the size and shape of the trains that can run on a particular network.