In some papers, it is used the Beijing ring road traffic data.
I searched the internet, But I didn't find the dataset.
For example, in a paper, it is noted:
"Beijing is the capital of China and one of the largest cities in the world. At present, Beijing is encircled by four two-way ring roads, that is, the second to fifth ring roads, and has about 10,000 taxis to serve its population of more than 21 million. These taxis are equipped with GPS devices that upload data approximately every minute. The uploaded data contain information, including car positions, recording time, moving directions, vehicle travel speeds, etc. The data were collected from 1 May 2015 to 6 June 2015 (37 days)."
How can I get them? Is there a site to download it?
Or do you know a good data set instead of it that contains the speed of vehicles?