Last year we stayed in Block 8 and didn't notice any road noise. durning the day we did hear a few airplanes take off since the local airport is right across the road but after dark it wasn't an issue.
We have been in room 4210, 3201 and room 8207 all of which I consider close to the road to hear any alleged road noise. With the exception of when you sit on the toilet to contemplate worldly matters we never had any problems with road noise. It is a NON issue so I wouldn't worry about it. Besides I guarantee you the tree frogs will lull you to sleep.
There is essentially two sides of CN. One on the lush tropical garden side and the other the more open ocean side. In all my visits I have yet to find a bad location or a building I wouldn't want to be in. All are a short distance away from the center of activities.
I have seen a few reviews about CN where the review mentioned "road" noise. Is there a certain building that should be avoided? Is there a building that is preferred? Thank you.
Note that even if you state a preference for a certain building it is a request, never a guarantee. If you're worried about noise, either have and extra glass of wine at dinner or book and ocean room. I've stayed in the garden rooms and don't recall being super uptight about the traffic...but others are definitely bothered by it. If you're a light sleeper you might want to consider the other 2 room categories.
We were in building 8 as well, on the third floor corner suite. We could hear the road noise. What helped a lot was closing the windows in the bathroom....otherwise the noise was not much and didn't really bother us at all.