The downgrading of a double-track mainline into a single-track route. This is typically done to reduce maintenance costs on routes where traffic volume has declined. The remaining single track is usually upgraded with centralized traffic control and passing sidings to handle opposing movements efficiently.
Heard on the job
They finished the singling project last fall, so now we've to wait in the hole at the new siding for the eastbound manifest.
Related terms
Double track
A railway line built with two parallel sets of tracks to allow simultaneous traffic in opposite directions.
Siding
A track alongside the main line, connected at both ends, where trains meet or let others pass.
Centralized traffic control
A signal system that allows a single dispatcher to line switches and signals across hundreds of miles of track.