The problem might be on my end, but the sirens are pretty quiet. Is there any way I can turn up the volume of them? Maybe in a .cfg file somewhere?

The UI apps doesn't show when I add them

AI are broken when using the traffic lights and either the mod is incompatible with a mod or a recent AI update.

Behaviour:
Ai seem stuck at traffic lights like the light is red all the time

It is definitely a conflict including your mod as it is the only one it happens on if it enabled.
If you do handle AI in any way on traffic lights, could you at least point me in the right direction and I'll see if I can figure it out, learning LUA in the process.