Seriously. Having only ridden in a few of China's many provinces, i think i can say without fear of contradiction that Zhejiang has the best roads. Go on google maps, pick one that looks twisty, you can pretty much be guaranteed that those industrious little geniuses will have paved it beautifully and then proceeded to reroute all the traffic via some other road.
Please direct your attention to my saturday ride, from Suzhou to Qiandaohu (1000 islands lake). In particular the last 100km:
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This is a tiny tiny local road across some mountains, there are only a few economically insignificant villages along it, probably only a couple of hundred people ever use it. Anywhere else in china it would be destroyed with no plans to ever repair it, but not in Zhejiang! The surface is immanculate, lovely smooth grippy tarmac, and not a straight line for 100km. And no traffic. Heaven.
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