Broad-gauge railway

A broad-gauge railway is a railway with a track gauge (the distance between the rails) broader than the 1,435 mm (4 ft 8+12 in) used by standard-gauge railways.

Broad gauge of 1,520 mm (4 ft 11+2732 in), more known as Russian gauge, is the dominant track gauge in former Soviet Union countries (CIS states, Baltic states, Georgia, Ukraine) and Mongolia. Broad gauge of 1,524 mm (5 ft), commonly known as Five foot gauge, is mainly used in Finland. Broad gauge of 1,600 mm (5 ft 3 in), commonly known as Irish gauge, is the dominant track gauge in Ireland, the Australian state of Victoria and Adelaide in South Australia and passenger trains of Brazil.

Broad gauge of 1,668 mm (5 ft 5+2132 in), commonly known as Iberian gauge, is the dominant track gauge in Spain and Portugal.

Broad gauge of 1,676 mm (5 ft 6 in), commonly known as Indian gauge, is the dominant track gauge in India, Pakistan, Bangladesh, Sri Lanka, Argentina, Chile, and on BART (Bay Area Rapid Transit) in the San Francisco Bay Area. This is the widest gauge in common use anywhere in the world. It is possible for trains on both Iberian gauge and Indian gauge to travel on each other's tracks with no modifications in the vast majority of cases.[citation needed]