Small Nuclear Power Plant

Help please. How to make a standard 4 way intersection work with signals? I’m placing path signals at each entry, block signals at each exit. But the intersection shows as occupied even though there’s no train there.

All running at 100% efficiency, making 6400 Aluminum Casing, 1200 Alclad Sheets, 1200 Empty Fluid Tanks and turning 1200 Aluminum Ingots into 750 Ficsite Trigons :)

My main factory relies on that center spine of components running through it and it seems to work well enough for now (aside from needing to increase my plate and rod production) And using tractors to transport far away coal to my smelter and coal plants (in the distance) is very useful. definetly way better looking than my first attempt at this game, which was to send a lvl 1 conveyer 3 miles down a hill to my coal plants.