In this video we show how to make a train traffic circle, or roundabout, enabling a 4-way intersection where trains can enter or leave on 8 separate tracks.
This tutorial shows how to build a basic traffic circle for trains in Factorio so that you can have a higher volume of trains passing through an intersection while giving each one the ability to leave in any of the 4 directions. Even if your intersection only has 3 directions currently being used, I recommend building a rail roundabout like this one in case of later expansion, and because they work so well at allowing trains to pass through quickly with lots of versatility. If you’re using longer trains you’ll want to expand the size of this design some, which is very simple as it currently has 4 straight tracks on each 4 sides of the circle — if you have longer trains, just add more. If you know you’ll only have 2-3 trains or many very short trains, you could even shorten it a bit.