As of 2020, which country is believed to have the most miles of motorway?

China is believed to have the most miles of expressway in the world.

The expressway network of China, with the national-level expressway system officially known as the National Trunk Highway System, is an integrated system of national and provincial-level expressways in China.

With the construction of the Shenyang–Dalian Expressway beginning between the cities of Shenyang and Dalian on 7 June 1984, the Chinese government started to take an interest in a national expressway system. The first modern at-grade China National Highways is the Shanghai–Jiading Expressway, opened in October 1988. The early 1990s saw the start of the country's massive plan to upgrade its network of roads. On 13 January 2005, Zhang Chunxian, China's Minister of Transport introduced the 7918 network, later renamed the 71118 network, composed of a grid of 7 radial expressways from Beijing, 9 north–south expressways (increased to 11), and 18 east–west expressways that would form the backbone of the national expressway system.

By the end of 2020, the total length of China's expressway network reached 161,000 kilometers (62,162 miles), the world's largest expressway system by length, having surpassed the overall length of the American Interstate Highway System in 2011.

The Jinggang’ao Expressway, which links Beijing to Hong Kong and Macao, is the country’s busiest highway. Every day some 140,000 tons of cargo travels this road and it’s the country’s No 1 expressway for congestion.