Single Track One-Direction Rail System Many of our railroads have one track that is used for freight and passenger traffic in both directions.  Scheduling is such that one-direction is used on even days of the week, and the opposite on the odd days.  Every so many miles there is a turn-out track that allows the freight train to move out of the way of a faster passenger train.  This system saved construction money and was fine during the days when trains were slow and only a few traveled the route per day or week.  Today's trains are faster and more are on the route at any given time, thus the single track rail system is becoming obsolete. Index of ... Single Line Operation Single Track Railway - Wikipedia