Many people are grateful to him for his contributions in fighting famine. When his body was transported, many people ran on the streets, shouting to the cars. Here's a video: https://twitter.com/Jingjing_Li/status/1396454905200533509
For context, in an event like this honking car horns is a sign of respect. Same as the remembrance of the 2008 Sichuan earthquake when all traffic stopped and blew their horns.