Protesters disrupted Monday morning traffic in D.C. as they demonstrated against the grand jury decision in Michael Brown's shooting death. (The Washington Post)

In Washington, the protest leaders include a D.C. bank manager, a retired government whistleblower and a radio producer who once ran for vice president on a socialist party ticket.

There’s no centralized movement. No coordinated planning. These are pop-up protests, emerging largely through social media, mostly happening across the city and the country since a grand jury chose not to indict Ferguson, Mo., police officer Darren Wilson in the fatal shooting of teenager Michael Brown.

Protests have sprung up in different forms and places: College students in Tennessee and St. Louis vowed to walk out of classrooms Monday, and St. Louis Rams players held up their hands in a “don’t shoot” gesture Sunday before they took the field. This week in Washington, the protests affected thousands of drivers as demonstrators shut down the 14th Street bridge Monday morning and Interstate 395 on the Sunday after Thanksgiving.

No national organization has emerged as the movement’s operations center. And no one knows exactly where the protests are headed. Instead, they have morphed into a constellation of disparate uprisings, from small affairs involving a half-dozen people to larger marches along busy thoroughfares, timed for maximum impact.

“I know that Sunday is the busiest travel day because it’s right after the holiday, so I wanted to impact the most people I possibly could,” said Toni Sanders, 31, a District bank manager who was one of several people standing in the middle of traffic on Sunday across I-395. “I think we had such a large impact because we’re here in the nation’s capital. A friend of mine said her mother in Palestine saw footage of us on the highway.”

On Monday, about 30 protesters caused street closures by lying in the road at Seventh and H streets NW, stopping in the 900 block of Constitution Avenue NW and blocking the northbound lanes of the 14th Street bridge during the morning rush hour. The action at the bridge backed up traffic on the George Washington Memorial Parkway as well.

The Ferguson-related protests are being mounted by different groups with different names.

Sanders, who said she was arrested and briefly jailed for the I-395 protest, runs a movement called Think MOOR, which stands for Movements of Organized Revolutionaries.

Marsha Coleman-Adebayo, 62, a retired whistleblower whose case prompted passage of an anti-discrimination and retaliation bill, helps lead protests under the name Hands Up Coalition DC. On Monday afternoon, her organization led a demonstration outside the Justice Department, where about 30 to 40 people sang, “We who believe in freedom cannot rest.” They also passed out “wanted” fliers with Wilson’s picture and chanted, “Arrest Darren Wilson now!”

Eugene Puryear, a producer for Liberation Radio who ran for vice president in 2008 on the Party for Socialism and Liberation ticket, attracts protesters under the banner of the DC Ferguson Movement. His group, whose leaders include a Howard University librarian and a community organizer at a local nonprofit, sparked rallies in Chinatown and Georgetown last week.

“We are going to launch a petition against police ‘jump-outs’ pretty soon,” Puryear promised, referring to a police tactic in which officers in unmarked cars suddenly stop people they suspect of crimes. “Blocking off streets and stopping business as usual, that’s a way to inject the urgency of now into this issue of police murders and police abuses.”

Some people have been sampling the different protests. Erika Totten, a self-proclaimed soccer mom from Alexandria, said she was one of the people arrested and jailed Sunday for blocking traffic on I-395.

On Monday, Totten, 32, was back at it, protesting in front of the Justice Department, leading others in a chant: “We must love each other and protect each other! We have nothing to lose but our chains.”

Totten said she’s protesting for her 5-year-old son and 4-year-old daughter. She said she tells her kids not to watch out for strangers but to “watch out for the cops.”

At Sunday’s protest on I-395, Sanders said, District police mostly treated her well. After she and several friends were put in a jail cell, “one officer looked at us and said, ‘Good job,’ ” Sanders said. “They were in solidarity with us.”

D.C. police say they closely monitor pop-up protests with officers who are trained to handle civil disturbances.

Officer Araz Alali, a department spokesman, said that when protesters block streets, they are given three warnings, and if they do not disperse, arrests are made. That occurred over the weekend when several protesters sat down in a downtown street near the Mall. A much larger protest, involving hundreds of people, went off without any arrests or problems last week.

Police in the District try to give protesters wide latitude to march and even take over streets as long as they keep moving. On Monday, police escorted and stayed behind protesters as a small group moved along Constitution Avenue, through the Third Street tunnel and up Seventh Street to the Justice Department building. No arrests were made.

“We generally try to avoid arresting people expressing their First Amendment views,” said Assistant D.C. Police Chief Peter Newsham. “If we can safely get protesters through the District of Columbia, we are going to allow that to happen.”

In Washington, protesters meet one another at demonstrations or learn about new ones through word of mouth. Some create pages on GoFundMe, a crowdfunding Web site, and find one another on Twitter, Facebook and Instagram. Twitter hashtags such as #DCFerguson or #BlackLivesMatter also help alert people to the latest events.

When eight protesters were arrested Sunday for blocking traffic on I-395, the remaining 15 or so gathered bail money and waited for them to be released, said Iman Hadieh, 38, an office manager who lives in Northeast Washington and was not arrested.

“I was tingling the whole time,” she said, “because I felt a sense of community that I don’t feel any other time.”

Dana Hedgpeth and Julie Zauzmer contributed to this report.