Thailand
total: 4,071 km
narrow gauge: 4,071 km 1.000-m gauge (2006)
Togo
total: 568 km
narrow gauge: 568 km 1.000-m gauge (2006)
Tunisia
total: 2,153 km
standard gauge: 471 km 1.435-m gauge
narrow gauge: 1,674 km 1.000-m gauge (65 km electrified)
dual gauge: 8 km 1.435 m and 1.000-m gauges (three rails) (2006)
Turkey
total: 8,697 km
standard gauge: 8,697 km 1.435-m gauge (1,920 km electrified) (2006)
Turkmenistan
total: 2,440 km
broad gauge: 2,440 km 1.520-m gauge (2006)
Uganda
total: 1,244 km
narrow gauge: 1,244 km 1.000-m gauge (2006)
Ukraine
total: 22,473 km
broad gauge: 22,473 km 1.524-m gauge (9,250 km electrified) (2006)
United Kingdom
total: 16,567 km
broad gauge: 303 km 1.600-m gauge (in Northern Ireland)
standard gauge: 16,264 km 1.435-m gauge (5,361 km electrified) (2006)
United States
total: 226,612 km
standard gauge: 226,612 km 1.435-m gauge (2005)
Uruguay
total: 2,073 km
standard gauge: 2,073 km 1.435-m gauge
note: 461 km have been taken out of service and 460 km are in
partial use (2006)