A report on COVID-19 in King County shows that transmission has dropped significantly since the outbreak began due to social distancing measures.

Prepared by the Institute for Disease Modeling in Bellevue, the report shows that the number of people who can be infected by someone with a positive case of COVID-19 remained near one as of April 9, down from roughly three other people when the outbreak began. This is known as the reproductive number.

“Policy action to reduce transmission further may be required to bring the daily case count down before partial relaxation of social distancing policies can occur without substantial risks to the community and healthcare system,” the report states.

Social distancing policies, which were enacted in March, have prevented infections from multiplying exponentially and overwhelming hospitals, according to the report. The rate of new infections in King County has held steady at about 100 new cases daily. The number of people each person with COVID-19 can infect has similarly held at about one since March 22.

The course of the pandemic will depend on people’s behavior, social distancing and other containment policies, according to the report, which outlined three paths the outbreak could follow.

If social distancing is partially relaxed on May 1, the model anticipates a rapid rise in new cases that would likely exceed recent peaks by the end of the month. If new strategies are adopted to fight the outbreak, the reproductive number could drop to 0.5 and case rates would fall.

The report doesn’t recommend policies, but it does lay out options. These include increasing physical distancing recommendations along with scaling up testing and contract-tracing operations.

Gov. Jay Inslee has been allowing certain portions of the economy to reopen in recent days. On April 24, he announced construction projects could resume if supervisors could show they’re following new safety guidelines amid the outbreak. Crews working low-risk projects that were underway during March will be allowed to continue, and construction workers must follow social distancing.

Beginning May 5, the state’s parks and forests will begin to reopen and allow activities such as hiking, fishing, hunting and golfing. But the state is asking people to not engage in these activities with people they don’t live with. If there’s an increase in COVID-19 infections, the state could reinstate restrictions and closures.

See the latest King County reports on COVID-19 cases here.