"春运"可谓中国专属，所以英译时可直接引用汉语拼音为"Chunyun"，也可以意译为"the Chinese Spring Festival travel rush(或season)","春运"英文介绍:

Chunyun refers to the extremely high traffic load of transportation in China around the time of Chinese New Year,which happens annually with millions of people rushing to their hometowns from where they work or study in order to catch up with the most important and special affair-family reunion.