Traces of lights

Brain Auer started a blog project, Photography Project: Blown Away, which calls for "a photo that exhibits overexposure, or blown-out highlights... and tell us about it — how you did it, why you did it, what it means to you, or any other thing you’d like."
Photos like this are often rejected as poor - and it sounds strange that he calls for this type of shots.
After digging deep into my photos taken earlier this year and some thinking and rethinking, I decided to post the following photo--one that fits the topic and looks passable:

Traffic of Wan Chai, part of the commercial centre in HK, at a Saturday night back in January this year. I did this as a long exposure exercise; and I thought the traffic transformed into traces of lights would look great, so I used the manual exposure mode and set the exposure time at 30 seconds, and ISO set at 80.
It was the the second attempt I made to capture the traffic - and this shot's better. The lights on the road are not too bright and the sky's not completely dark; moreover, there's a reflection of a neon light on right side of the shot. The other one were taken at 19:21 on 28 December 2006, the traffic lights were way overexposed while the sky looks featureless and dull. Click here to look at the shot.

What I like about this shot is that it is one that moderately overexposed, details can still be seen; the lights at the bottom of the picture aren't dazzled. The shot didn't come easily and it's one of the long exposure photo that I got the exposure right - I even thought it was one of my best photos when it was newly produced! Though it doesn't look as impressive or beautiful to me now as it once was - it's still a shot that carries some importance.
After all, it's not easy for an inexperienced snapshooter to get it right with photos like this.