I'm pretty sure some of you saw this on the BeamNG Reddit, but I'll put it here as a suggestion too. This image shows both the H-series' Simple traffic model and the normal one. Don't you notice anything a bit odd? It's not just you, the simple traffic model CLEARLY has better headlights than the normal one. Which is, I mean, eh? Come on devs, please fix.
All headlights for vehicles are PBR, is just that the new Simple traffic have their own textures which they all share. The reason the simple traffic lights are brighter is because the shared glass texture has a set opacity for all vehicle glass.