The original email containing these pictures said this road is in Bolivia, and the name means "road of death". However, later checking indicates that it is actually Gualiang Tunnel, which is near Mount Taihang, near Beijing, China. One of the early sites containing this images is: on the Skycraper forum. In turn, that points to a Chinese-language site that includes many more pictures of the area. I've taken the sign image from there.
A newer image