It took Thomas Streetman two hours to walk out his front door, take a cab to the public health center, get tested for the coronavirus and make it back to his apartment. He, who works as a marketing manager at a gaming company in Seoul, received his negative results in less than 24 hours and is now one of more than 327,000 people out of the country’s 51 million-strong population to have been tested for the coronavirus in South Korea since the country confirmed its first case Jan. 21.

Since March 11, South Korea has seen a general decline in the number of new coronavirus cases, some as low as 74 and 76 each day — a stark comparison to its peak of 909 cases Feb. 29.

News that China had reported its first case of the coronavirus was enough reason for South Korean leaders and medical staff to brace themselves for the worst. “Acting fast was the most important decision South Korea made,” said Hwang Seung-Sik, a professor at Seoul National University’s Graduate School of Public Health. Active collaboration among central and regional government officials and medical staff took place before cases began piling up, enabling South Korea’s current testing capacity of 20,000 people a day at 633 sites, including drive-thru centers and even phone booths. Under South Korea’s single-payer health care system, getting tested costs $134. But with a doctor’s referral or for those who’ve made contact with an infected person, testing is free.

South Korean leaders have amped up efficiency for overwhelmed hospitals by digitally monitoring lower-risk patients under quarantine, as well as keeping close tabs on visiting travelers who are required to enter their symptoms into an app. Sites like Corona Map generate real-time updates about where current patients are located and inform proactive Koreans focused on protecting themselves.

Commuters wait at platforms and in subway cars as announcements are played in different languages, including English and Chinese. A female voice lists tips such as “blocking” your mouth when coughing. Now, hand sanitizer bottles are placed in front of nearly every entrance and elevator for public use. And of the 1,000 people who took part in a study by Seoul National University, 97.6 percent responded that they at least sometimes wear a mask when they are outside, 63.6 percent of whom said they always wear one.

South Korea has already started new testing on all arrivals from Europe, according to local news reports, preparing for a “second wave” of imported clusters. Even those who test negative are required to self-quarantine for 14 days. “We are proceeding with cautious hopefulness,” Hwang said.