The center of the city is where most people can reach in 30 minutes.
These time and space and relationships were true when people were walking, riding horses, biking, or driving.
China is spending hundreds of billions and eventually trillions to integrate multiple cities into larger megacities (cities and suburbs around Beijing, cities around Shanghai and near Hong Kong). China is using high speed rail to increase the distance that can be reached in about one hour.
The trains will be going at 200-300 mph and later at 400-600 mph. At peak times they leave about every 5 to ten minutes.
The US Northeast has something that claims to be high speed. The route contains segments of “high-speed rail”. Acela Express trains are the fastest trainsets in the Americas; they attain 150 mph (240 km/h) on 28 miles (45 km) of the route.
The Acela is limited by both traffic and infrastructure. On the 231-mile (372 km) section from Boston’s South Station to New York’s Penn Station, the scheduled time is 3 hours and 40 minutes, or an average speed of 63 miles per hour (101 km/h). Along this section, Acela has still captured 54% share of the combined train and air market. The entire 457-mile (735 km) route from Boston to Washington takes 7 hours, at an average of around 65 miles per hour (105 km/h).
Average speeds of 60-65 mph are not high speed by any definition.
Once an hour trips that take just short of four hours or up to 7 hours are not close to one hour.
Acela carried more than 3.4 million passengers in fiscal year 2015. This is about ten thousand people per day.
The US also can have less than one hour plane flights to connect some cities. However, the minimum time in the airport or getting out of air ports is over one hour on each end. Thus totals of over three hour times mean that short haul airplane travel is not enabling the creation of a connected city.
910 million trips were fulfilled by China’s HSR in 2015, about 3 times of the HSR traffic volume in Japan, 8 times of France’s, or equivalent to total air flight traffic volume in the US. Traffic has been growing at 39% per annum since 2008 to 2014. Average speed is about 330 kilometers per hour.
A new line between Beijing and Tianjin cut travel times from three hours to 37 minutes.
So a portion of the people can get across the megacity in under one hour. This is heading towards meeting the definition of a city, but it is far from meeting the criteria of overall one hour travel times.
A new $36 billion rail plan was recently approved by China’s National Development and Reform Commission which will further integrate the cities of Beijing and Tianjin and parts of Hebei province into a sprawling megaregion dubbed Jing-Jin-Ji. This infrastructure building endeavor will include of a total of nine projects that will consist of 1,100 kilometers of new track being laid by 2020.
China could add 50 more lines by 2050 for each megacity or megaregion. This is to stitch together more points across the area.
Getting to over ten lines connecting the area in under an hour is starting to become significant integration.
50-60 lines will be fairly meaningful integration of the cities into one megacity.
The Jing-Jin-Ji megaregion contains over 110 million people and cover 212,000 square kilometers, which is roughly 87% of the total area of the UK.
In addition to Jing-Jin-Ji, China is currently building around nine other such megacity clusters across the country, which include one consisting of 16 cities and 80 million people in Yangtze River Delta (around Shanghai) and another which draws together 11 cities another 80 million people in the Pearl River Delta (around Hong Kong and Shenzhen and Guangzhou).