Einzelspur

Einzelspur, or single-track, is a railway line that has only one running track over most of its length. Trains traveling in opposite directions share the same track, which requires careful scheduling and the use of passing places.

Where trains meet, designated passing loops or sidings allow one train to wait while another passes. The line is divided into blocks, and occupancy of a block is restricted to one train at a time to prevent head-on conflicts.

Operational systems range from traditional token or staff methods to modern block signaling and radio-based control. In practice, capacity on a single-track line depends on the length and location of passing places, as well as the reliability of timetables.

Upgrading to double track eliminates many of these constraints but involves substantial construction work and cost. Single-track operation remains common on rural, mountainous, or lightly trafficked routes and on lines where geography or economics limit expansion.

Historically widespread, single-track operation persists on many rural or mountainous lines where capacity needs are modest and construction costs are high. It is a core concept in railway operations and contrasts with double-track lines, where two tracks permit continuous two-way traffic with higher capacity.