In planning for the inauguration, officials are looking at the biggest crowd possible, D.C. Mayor Muriel Bowser said.
The mayor did not make a crowd prediction, but said planners are preparing for all contingencies. They are looking at the 2009 inauguration, which more than 1 million people attended.
Bowser and other District and federal officials held a briefing Friday on logistics for Inauguration Day.
Planning for the inaugural began in April.
"Every four years, our government works overtime to keep everyone safe during the peaceful transition of power," Bowser said.
Something setting President-elect Donald Trump's inaugural apart from others is the unprecedented number of protestors expected.
"Our goal is always to make sure people can come express their rights peacefully and lawfully regardless of subject matter and return home safely at the end of the day," said Chris Geldart of D.C. Homeland Security and Emergency Management.
“We are well-prepared and ready for this inauguration,” U.S. Secret Service Special Agent in Charge Brian Ebert said.
Law enforcement partners created 25 subcommittees to plan for security, Ebert said.
In addition to the Metropolitan Police Department force, another 3,000 police officers and 5,000 members of the National Guard will provide security at the inauguration, Bowser said.
"The fact that you have some people indicating on social media that they're coming to shut down inaugural events is something we're prepared for," D.C. Interim Police Chief Peter Newsham said.
The marijuana advocates who plan to hand out thousands of joints to be lit four minutes and 20 seconds into Trump's speech will not be a priority for police.
Also for security reasons, Metro will close the Mt. Vernon Square, Archives, Federal Triangle, Smithsonian and Pentagon Metro stations on Inauguration Day, Metro General Manager Paul Wiedefeld said.
The rail system will open at 4 a.m. and close at midnight, with peak service from 4 a.m. to 9 p.m., Wiedefeld said.
The SafeTrack project already is on hold. Suspending work during the inauguration factored into the original SafeTrack plan, Wiedefeld said.
The Arlington Memorial Bridge will be closed to vehicles but open to pedestrians. The National Park Service still needs another $200 million to complete repairs on the bridge, Bowser said.
Bowser said the inauguration will cost $30 million, for which she expects the federal government to pay.
No one was able to say how many permits to gather for protests have been or will be granted, saying authorities are still working those logistics out with the Presidential Inaugural Committee.