National Trunk Highway System

The expressway network of China is an integrated system of national and provincial-level expressways in China. It is the world's largest expressway system by length, having surpassed the overall length of the American Interstate Highway System in 2011. Between the end of 2014 and 2015, the total length of the network grew from 111,950 kilometres (69,560 mi) to 123,000 kilometres (76,000 mi) meaning 11,050 kilometres (6,870 mi) of expressway were built in 2015 alone. A system of national-level expressways, officially known as the National Trunk Highway System (simplified Chinese: 中国国家高速公路网; traditional Chinese: 中國國家高速公路網; pinyin: Zhōngguó Guójiā Gāosù Gōnglùwǎng) and abbreviated NTHS, with 7 radial expressways (from the capital Beijing), 11 north-south expressways and 18 east-west expressways, forms the backbone of the expressway network in the country. This backbone is known as the 71118 network (simplified Chinese: 71118网; traditional Chinese: 71118網; pinyin: 71118 wǎng). In addition, the provincial-level divisions of China each have their own expressway systems.

Expressways in China are a fairly recent addition to the transportation infrastructure in the country. Previously, the national road network consisted of a system of at-grade China National Highways. China's first expressway, the Shanghai–Jiading Expressway, opened in October 1988. This 17.37 kilometres (10.79 mi) expressway now forms part of Shanghai's expressway network. The early 1990s saw the start of the country's massive plan to upgrade its network of roads. In 1999, the length of the network exceeded 10,000 kilometres (6,200 mi) in length. Many of the major expressways parallel routes of the older China National Highways.

...
Wikipedia