Togo
total: 532 km
narrow gauge: 532 km 1.000-m gauge (2008)

Tunisia
total: 2,159 km
standard gauge: 471 km 1.435-m gauge
narrow gauge: 1,688 km 1.000-m gauge (65 km electrified) (2008)

Turkey
total: 8,697 km
standard gauge: 8,697 km 1.435-m gauge (1,920 km electrified) (2008)

Turkmenistan
total: 2,980 km
broad gauge: 2,980 km 1.520-m gauge (2008)

Uganda
total: 1,244 km
narrow gauge: 1,244 km 1.000-m gauge (2008)

Ukraine
total: 21,655 km
broad gauge: 21,655 km 1.524-m gauge (9,729 km electrified) (2008)

United Kingdom
total: 16,454 km
broad gauge: 303 km 1.600-m gauge (in Northern Ireland)
standard gauge: 16,151 km 1.435-m gauge (5,248 km electrified) (2008)

United States
total: 226,427 km
standard gauge: 226,427 km 1.435-m gauge (2007)

Uruguay
total: 1,641 km
standard gauge: 1,641 km 1.435-m gauge (2008)

Uzbekistan
total: 3,645 km
broad gauge: 3,645 km 1.520-m gauge (620 km electrified) (2008)