Traffic congestion will be so bad that federal employees in the Washington area should try not to come into work when Pope Francis comes to town for three days this month, the government said Tuesday.

While federal offices will stay open from Sept. 22 through Sept. 24, the Office of Personnel Management is urging agencies to let employees with work-from-home arrangements use them.

“Due to the increase in traffic, road closures, significant detours, crowded trains and buses, longer wait times at stops and stations, and related commuting disruptions on these days, federal employees who work in the Washington, D.C., [region] should expect significant commuting delays and travel disruptions,” Beth Cobert, OPM’s acting director, wrote in a memorandum.

OPM “strongly encourages agencies to allow employees to telework to keep the government operating,” she said.

The pope’s visit is expected to attract tens of thousands of people to the Capitol area during his speech, and many more on the Mall. The government is bracing for big logistics challenges.

[Visiting Pope Francis in Philadelphia? Leave your drones and selfie sticks behind ]

Cobert suggested that employees “who can be spared from their duties” consider taking a day off, leave without pay or previously earned comp time during the pope’s visit. If people have to go into work, they should allow extra time for commuting.

Businesses and nonprofits often follow the government’s lead’s on weather-related closings.

The telework arrangements won’t be exactly the same as snow days, though. Often the government closes in bad weather, giving federal workers a day off they would otherwise not have to take.

Over the course of three days, the pope will see the sights of Washington, meet with President Obama at the White House and address a joint session of Congress before he heads to New York and then Philadelphia.

Here’s the schedule for the papal visit.

Stay up to date on the upcoming papal visit. Sign up here to follow Washington Post stories about Pope Francis’ visit to the United States and we’ll e-mail you as they are published.