Hello Soren,
I like both these pictures and your previous ones of the bridge.
So far, I found my D70 to have truly "film like" reactions in every situations including night shots. The patterns arround the light seems a bit extreme at first glance but I don't think it is that surprising considering the 15 sec exposure. I have experienced similar patterns (smaller though) with exposure times arround 8 or 10 seconds.
regards
Seb