A dozen years after it broke ground, Ho Chi Minh City has unveiled its first subway line in Vietnam’s largest city.

After years of funding shortages, ballooning costs and bureaucratic foot-dragging, Ho Chi Minh City is opening the first metro line to serve its 10 million residents.

Thousands of selfie-taking Ho Chi Minh City residents crammed into train carriages Sunday as the traffic-clogged business hub celebrated the opening of its first-ever metro line after years of delays.

At 6:15 am, a route No. 31 bus driven by N.B.D., 50, collided with a motorbike ridden by 60-year-old H.K.C., a resident of Binh Thanh District, as well as a bicycle ridden by a man. The impact caused both riders to fall onto the road.

The Metro Line No. 1 of Ho Chi Minh City running from Ben Thanh to Suoi Tien will be open for free for one month after its official inauguration ceremony on December 22. In the following days, the stations are open from 5am to 10pm. every day, with trains running every 8 to 12 minutes. There are 31 bus routes connecting to the Metro Line No. 1.

Hundreds queued and some broke into song for their first ride on the 19.7-km Ho Chi Minh City Metro Line No. 1. The city of nearly 10 million was one of Asia's last major urban centers not to have a metro.

Years of start-and-stop construction means the seemingly new ticket vending machines are partly obsolete: they accept coins that are no longer in circulation.