China ushered in its largest annual population migration on Tuesday, 15 days ahead of the Spring Festival, also known as Chinese Lunar New Year.

This marks the first chunyun, or Spring Festival travel rush, after UNESCO inscribed the Spring Festival on its intangible cultural heritage list in December last year.

Nine billion passenger trips are expected during this year's travel rush period that ends on Feb. 22 -- with both rail and air passenger trips set to hit record highs.

During this travel season, 7.2 billion road trips and over 90 million civil aviation trips are forecast to be made. More than 510 million passenger trips will also be handled by the country's railways, with an average of 12.75 million trips daily, an increase of 5.5 percent compared with 2024.

About 10.3 million train trips are expected to be made on Tuesday, the first day of the travel rush.

The public's desire to travel is strong, and overall passenger flow is expected to grow steadily during the travel rush, according to China State Railway Group Co., Ltd.

To meet the surging demand, China's railway operator will increase passenger transport capacity. Over 14,000 passenger trains will be operated daily on average during chunyun this year -- providing an additional 500,000 seats per day. Railway passenger transport capacity is expected to grow by about 4 percent year on year.

This 40-day travel surge will see hundreds of millions of people in China returning to their hometowns for family reunions.