This story is one in our six-part series The Pandemic Playbook. Explore all the stories here.

Every January or February, Le The Linh and his wife pack their children into their car and drive 80 miles to visit family in Haiphong, a port city east of Vietnam’s capital, Hanoi, for Lunar New Year. But this time, as they reached the last stretch of the Hanoi-Haiphong Highway, a police officer approached and pointed them toward a group of guards in face masks under a makeshift tent. It was one of 16 checkpoints erected around Haiphong to control travel into and out of the city ahead of the Tet Festival holiday.

They joined a lineup of other travelers, nervously waiting for their turn in the rain. When they reached the front, the officials asked for proof of their travel plans, residency, and Covid-19 status.

“Don’t worry!” Linh exclaimed tensely. He could show, with his identity card, that they lived in an area that had no coronavirus cases recently.

The family was among the lucky ones let through. Travelers from areas near Haiphong that had recently recorded Covid-19 cases got turned away; a group of young people on motorbikes who tried to circumvent the checkpoint were arrested; still others chose not to travel at all, opting to meet family over FaceTime or Zalo (Vietnam’s answer to WhatsApp).