Yeah now that you point that out to me it stands out every time I use it. It would be a nice touch to have small lights in the tunnel. However, I do think the developers have more important things to do, but they probably will add it once the map is finished (hence the wip on the map selection)
As with the mysterious bump - I have no idea! I just spin around in the tunnel like crazy anyway
, so I'm probably on the roof or something when I get to that bit.