double-track railway

rail pair multiplexing

bi-directional signaling, directional running, Double-line, Double-line railway, Double-lined, double-liner, Double-liners, Double-lines, Double-lining, Double-linings, double-track, Double-tracker, Double-trackers, Double-tracks, double line, Double lined, Double liner, Double liners, Double lines, Double lining, Double linings, double track, double track line, Double track railway, Double tracker, Double trackers, double tracks, Doubleline, Doublelined, Doublelines, dual-track railway, dual track (rail), Left-hand rail, Left-hand rails, left-hand running, Left-hand train, Left-hand trains, Parallel track, Rail handedness, Rail side, Rail sides, Right-hand rail, Right-hand rails, right-hand running, Right-hand train, Right-hand trains, track duplication, Train handedness, Train side, Train sides, Trains on left, Trains on right, Trains on the left, Trains on the right, Triple-track railway, Twin track (rail)

double track, quadruple track, triple track