I’m positive that I split my splines into groups in the past, but there is a good chance that I only did that for the initial setup to keep things organized. I’ll have to look through some of my older maps. I do know that I eventually have them all in a single TG because it causes issues with Autodrive, like I said.

Splines within GE are only designed to go in a single direction, so you would need two splines for multi-direction traffic. A single spline that could handle multi-direction traffic would get messy because the traffic only works on a simple collision system, and doesn’t have any way to know if a spline is already occupied before entering. You would  constantly have vehicles coming head to head.

I’ll look over the user attributes for the traffic splines just in case there is anything I’m missing, but I don’t believe that’s the case. Also, you can have more than one traffic system if need be. Different splines can be on different traffic systems, and I’ve seen some interesting things done with that in the past.