The primary gauge of the German railroad network (Deutsche Bahn) is the Standard Gauge, which measures 1,435 mm (4 feet 8.5 inches). This is the most widely used railway gauge in the world and allows for seamless interoperability between Germany and its nine neighboring European nations, such as France, Austria, and Poland. While the standard gauge dominates the mainline and high-speed ICE (Intercity-Express) networks, there are a few exceptions. For example, some historic or tourist "Harz Narrow Gauge Railways" in the Harz Mountains use a 1,000 mm (meter gauge). Additionally, some industrial lines or tram systems might feature slight variations. However, for almost all passenger and freight travel across the country in 2026, the 1,435 mm standard gauge remains the backbone of the German infrastructure, ensuring high-speed efficiency across the continent.