Wiktionary
a. (context railways English) Having only a single track so that trains may only run in one direction at a time
Usage examples of "single-track".
The booking office was closed because upon this single-track line there were only two trains a day, but the station-master lived beside the station in a weatherboard house, and he asked there for Mr Shulkin.
As on all single-track roads in the Highlands, passing places are provided -half-moon-shaped areas scooped out of the side to allow a driver to slip in and allow an oncoming car to continue.
The high limestone walls had kept the weak February sunshine off the single-track road and it was still heavily rimed with frost, save where previous traffic had exposed the black tarmac.
It was a single-track road with passing-places, so he was relieved, if a little surprised, not to meet any traffic coming in the opposite direction.
I drive the car up the little single-track road leading towards the low hills.
It's a single-track road, with room enough for one and a half cars, but not two.