Im having an issue where my decal roads glitch. I have the render priority set correctly, it was all actually working until recently, Im not sure what triggered this. Could it be the huge number of decal roads in my map? Or is there an easy fix. Ive messed with the Z bias and nothing changes. Its not my graphics card because the problem is the same on multiple PCs.
The Z fighting looks like you are using the same priority for the road and the lines. You need to use a smaller number for lines to be on top of the road. I think bias are ignored now because of render optimisations