China National Highway 108 (G108) is a National Highway which connects Beijing through Chengdu to Kunming. In Beijing it is known as Jingyuan Road.
Map of G108, China
It leaves Beijing at Fuxingmen and heads for Yamenkou, before heading into hillier terrain and leaving Beijing altogether. Both Tanzhe Temple and Jietai Temple are located nearby.
The section to the 4th Ring Road (Beijing) is under construction as a city express road, and the same applies for the stretch to the 6th Ring Road.
References
China National Highway 108 Wikipedia(Text) CC BY-SA