What track gauge is used by most Spanish high-speed railway lines?

Most Spanish high-speed railway lines use the standard gauge of 1,435 millimetres. This differs from the historic Iberian gauge of 1,668 millimetres used by much of Spain’s conventional railway network.

Spain began building high-speed lines with standard gauge so trains could connect more easily with the wider European high-speed network. The first Spanish high-speed line, between Madrid and Seville, opened in 1992.

The gauge difference creates an important operational distinction. Conventional trains may need gauge-changing equipment or specially designed wheelsets when traveling between networks, while standard-gauge high-speed trains use dedicated infrastructure.

Spain therefore has two major railway-gauge traditions. The standard-gauge high-speed network is extensive, but it does not mean every Spanish railway uses standard gauge. Regional, freight, and older main lines may retain Iberian or metre gauge.