^交通运输部公路科学研究院; 交通运输部科学研究院; 交通运输部规划研究院 (2017-09-07). 公路路线标识规则和国道编号 [Mark rules of highway route and number of national trunk highway] (in Chinese (China)). 中国标准出版社. p. 11. Retrieved 14 March 2023. G112 北京环线公路 京环线 12、13 [G112 Beijing Orbital Highway Jinghuanxian 12 (Tianjin), 13 (Hebei)]
China National Highway 112 runs around Beijing
Before 2013, Mainland China observed National Highway 228 as Taiwan Ring, composed of several National Expressway (Republic of China) and Taiwan provincial highways, this designation is not recognized by Republic of China (Taiwan). This observation was eventually dropped in new National Highway plans, replaced by Dandong-Dongxing Highway.
A extension plan of the highway system was announced in 2013, including extension of existing highways(101-112, 201-227, 301-330) and new highways (North-South 228-248, East-West 331-361, Connections 501-581). Only small portions of them needs to be constructed from scratch; most of the new highways would be upgraded provincial/county highways.
Another extension plan was announced in 2022, including new small purpose connection highways (601-701).