China has unveiled a plan outlining major targets for transportation network development in the 14th Five-Year Plan period (2021-2025).

High-speed railways will stretch to a total length of 50,000 kilometers in 2025, up from 38,000 km in 2020, and 250-km ones are expected to cover 95 percent of cities with populations above 500,000, according to the document released by the State Council.

The country will have a total length of 165,000 km of railways in 2025, up from 146,000 km five years earlier; more than 270 civil airports, up from 241; 10,000 km of subway lines in urban areas, up from 6,600 km; 190,000 km of expressways, up from 161,000 km; and 18,500 km of high-level inland waterways, up from 16,100 km.

The transportation system will also be greener. Cities will see 72 percent of buses powered by new energy, an improvement from 66.2 percent, and the carbon dioxide emission intensity will drop by 5 percent.

The main goal is to achieve integrated development in 2025, with tangible breakthroughs in the intelligent and green transformation of the transportation system, according to the plan.

Looking to 2035, the plan aims to build "1-2-3 circles" for passenger trips and the transportation of goods.

That means travel time within cities and city clusters, and among metropolises will be cut to one hour, two hours and three hours, respectively. Mails sent by express services may be be delivered in as short as one day within China, two days when sent to neighboring countries, and three days when sent to major cities globally.

In 2025, grain, energy and ore transportation safety in major channels will have a stronger guarantee, and international logistics supply chains will be better protected, according to the plan.

International connectivity will also be improved, the plan said, specifying efforts to enhance transportation infrastructure with neighboring countries, push for the high-quality development of China-Europe freight train routes, and build an "Air Silk Road," among others.