In 2003 a highway was being constructed between Nha Trang and Cam ranh. It was a road to serve all the new resorts that were being built on the coast on that stretch and the Chinese were the contractors. Four years later the road was two thirds complete and the portions already finished were crumbling. The locals, when the road was mentioned, just shrugged and say, "Made in China."
The rpad was rebuilt using, I believe Korean contractors and is a fine four lane road. The median is still kept trimmed by very efficient goats.
Four years later the road was two thirds complete and the portions already finished were crumbling. In one of the China-in-Africa books I read, the road building would start out OK, but then the higher ups would want a piece of the action, so the builder had to thin out the paving, which resulted in the effects you describe.