The Gauges of U.S. Railroads: From Standard to Narrow

The question of whether every track in the U.S. is used by a single railroad isn't straightforward. It depends on what you mean by 'one track.' In terms of track gauge, the overwhelming majority of railroads in the U.S. use the standard gauge, which is a critical specification ensuring compatibility and efficiency across the network.

Standard Gauge: The Dominant Standard

Almost all trains in the United States run on standard gauge, with a width of 1435 millimeters (4 ft 8.5 inches). This gauge is used in most of Europe and is the most common globally. Interestingly, this seemingly odd measurement originated from a mistake. The original measurement of 5 ft was realized to be more practical when measured as the space between the rails, rather than from rail center to rail center.

Other Gauges in the U.S.

While the standard gauge dominates, there are a few other gauges in use, particularly in specific regions or for niche applications.

Narrow Gauge Railways

Narrow gauge railways, typically with a gauge of 1,000 mm (3 ft 3.38 in), are used in certain areas, predominantly for historical and tourist purposes. This type of railway is cheaper to build and can make tighter turns, making it ideal for limited-access locations such as mines, seaports, or industrial operations. However, they require cargo to be reloaded onto standard gauge freight cars for wider distribution.

The Brazilian railways use a narrow gauge called Metre Gauge, with a width of 1,000 mm. Narrow gauge is also used in certain urban transit systems. For instance, Toronto's subway uses a gauge of 4 ft 10.78 in (1,495 mm), while the BART system serving San Francisco and Oakland utilizes 1,676 mm (5 ft 6 in), similar to India.

Other Gauges: Russian and Sub-Saharan African Gauges

The other notable gauges in the U.S. are Russian and Sub-Saharan African gauges. Russian gauge, with a width of 1,520 mm (5 ft), is used in parts of Russia, the Soviet Union, and Eastern Europe. While these regions are undergoing modernization, transitioning to the standard gauge to integrate better with Central and Western Europe.

Sub-Saharan Africa frequently uses a gauge of 1,067 mm (3 ft 6 in), often associated with the Cape Government Railroad and termed Cape Gauge. This network extends through South Africa and connects several countries including the Democratic Republic of the Congo, Angola, Zambia, Mozambique, Zimbabwe, Botswana, and Namibia.

Freight Network and Standard Gauge

The freight network in the U.S. is well-established and heavily utilized, compared to passenger traffic. The bulk of freight on the U.S. railroads travels on standard gauge tracks, ensuring compatibility across the network. Major urban areas like New York City see a significant portion of their rail traffic (approximately 80%) using standard gauge.

Key Points to Remember

The standard gauge dominates U.S. railroads with a width of 1,435 mm (4 ft 8.5 inches). Narrow gauge railways are used in specific niche applications, such as mining and tourist railroads. Other gauges include Russian and Sub-Saharan African gauges, which are undergoing modernization and transitioning to standard gauge. U.S. freight networks are well-established and predominantly use standard gauge tracks.

In conclusion, the rail network in the U.S. primarily operates on standard gauge, with only limited use of other gauges in specific regions or for specialized purposes. The standard gauge ensures compatibility and efficiency across the network, making it the de facto standard for most rail operations in the United States.