Metre gauge refers to railway track in which the two rails are spaced one thousand millimetres apart. It is one of the most common narrow gauges worldwide and has been adopted for routes where lower construction costs, tighter curves and lighter infrastructure provide advantages over wider gauges.

Characteristics

With a nominal separation of 1000 millimetres, metre-gauge track permits smaller loading gauges and lighter rolling stock than broader gauges. The reduced width allows sharper curvature and steeper gradients, making it suitable for mountainous terrain and lines with constrained rights-of-way. Compared with standard gauge, metre gauge generally limits maximum axle loads and potential top speeds, which affects line capacity for heavy freight and high-speed passenger services.

History and distribution

Metre gauge emerged during the 19th century as a pragmatic compromise for secondary and colonial rail networks. It was widely constructed in parts of Africa, South and Southeast Asia, South America and in some European regions. In many countries its prevalence reflects historical economic and geographic considerations rather than a single technical standard.

During the 20th and 21st centuries some metre-gauge lines have been converted to wider gauges or replaced by new standard-gauge routes to improve interoperability and capacity. Others remain in regular use where their operational advantages outweigh the benefits of gauge uniformity.

Uses, challenges and adaptations

Typical uses include regional passenger services, mountain railways, local freight operations and heritage lines. Operational challenges include breaks of gauge at junctions with different track widths, which require transshipment, bogie-exchange systems or dual-gauge track. Modern adaptations—such as specialized rolling stock, improved track materials and selective line upgrades—allow many metre-gauge networks to remain competitive for their intended roles.

  • Advantages: lower civil-engineering costs, sharper curves, easier construction in difficult terrain.
  • Disadvantages: lower axle loads, reduced speeds and complications at gauge breaks.
  • Notable facts: metre-gauge remains important for regional mobility and some famous mountain lines, while gauge conversion programs reflect changing transport priorities.