No disrespect but why the separate thread from the HDR thread?
The most successful night shots, IMO, are taken during the 'magic hour': after the sun has gone down, but while there's still light in the sky.
In most of these shots, there's a lot of very dark sky - almost black - and not enough bridge. This contrast makes the bridge almost invisible in some shots. Try to shoot a bit earlier, while the ambient light and artificial lights are more 'in balance'...
No disrespect but why the separate thread from the HDR thread?
I like the 1st example and really like the 4th one, the light under the bridge made that one so much better, which will go with Doylem's comment about lighting.
To be honest, I was liking the HDR thread...but it got so big I gave up trying to look through it.
I only tried HDR once - I think I took 3 shots and -1,0,+1 (or something like that), and merged them in Photoshop - the results weren't too impressive. .