Plans and security preparations have been in the works for months in anticipation of the 58th Presidential Inauguration on Friday, and those whose duty it is to protect the ceremony and its festivities are taking no chances.

Protection of the events spanning three days from Thursday through Saturday is tasked to over 28,000 law enforcement officers and other officials. Personnel from Homeland Security, the Secret Service, Coast Guard and police departments from across the country and the Washington, D.C. metro area will deploy with approximately 7,800 National Guard troops.

In addition to threat of terror attacks, those securing the area will need to be concerned with protestors attempting to disrupt traffic, checkpoints and the events themselves. Nearly 100 groups have registered for protest permits, more than 10 times the usual number at previous inaugurations.

Authorities are also concerned that those from out of town may attempt to bring firearms into secure locations. Regardless of local law, the U.S. Secret Service prohibits any firearms from entering the secure zone even if the individual has the right to carry in D.C.

After a security briefing and event run-through on Friday in a secure location in Northern Virginia, Homeland Security Secretary Jeh Johnson had this to say (via USA Today):

Johnson said Friday that while there were “no specific or credible threats” targeting the inauguration events, security forces were “doubling down” to thwart the type of vehicle attacks that killed 12 last month at a Berlin Christmas market and left 86 dead at a July Bastille Day celebration in Nice.

Johnson said heavy construction equipment, dumpsters and other physical barriers were being strategically placed around the city. The barriers will restrict vehicle access to sensitive areas and assist with crowd control during three days of activities when up to 900,000 people are expected to flood the city.

“The global terror environment is very different even from 2013,” the secretary said, referring to the last inaugural ceremony marking Obama’s second term. “We have to be concerned about individual acts of violent extremism.”

Essentially, all of downtown D.C. will be a vehicle restricted zone, allowing only government officials through the outer perimeter, with many total road closures to assist in keeping things secure.