Blitz, it depends on the available light in that area.
Most night scenes of a city's skyline will have exposures of about 30s. For eg, you take skyline of our city from sheares bridge. Also, if you go HK and take night scene from Victoria Peak.
The conclusion, is, you pic is over expose probably becoz the area in the pic is quite well-lit. So you dun need a 16s exposure.
As for funny pixels, most DC are not able to handle long exposures very well.