The engineering and construction process of widening a rail corridor to accommodate four parallel running lines. This layout typically separates traffic by speed or direction, dedicating two tracks for fast or passenger trains and two for slow or freight trains. It drastically increases route capacity and eliminates bottlenecks on busy main lines.
Heard on the job
They're four-tracking the corridor out to the junction to keep the commuters from delaying our intermodal drags.
Also heard as
- quadruple track
Related terms
Double track
A railway line built with two parallel sets of tracks to allow simultaneous traffic in opposite directions.
Main line
The principal track or tracks of a railroad between terminals, where trains need authority to run.
Multitrack
Describing a railway line or corridor equipped with two or more parallel tracks.