CHICAGO (CBS) – For the first time, organizers of May’s NATO summit have laid out some details of security and crowd control plans that will be in place downtown and near McCormick Place.

CBS 2’s Vince Gerasole reports a former Secret Service agent advising City Hall on security measures provided some insight on how City Hall is preparing for the two-day summit of leaders from 50 nations. He’s advising officials that public transit should not be affected by security plans.

Without the G8 summit scheduled for the same weekend now moved to Camp David, fewer violent protestors are expected in Chicago.

Downtown businesses are now being briefed about what to expect. So far, it’s a plan to keep the city feeling and looking normal, with few closures limiting access to public transportation and the Loop.

The tenants at The Fine Arts Building, at 410 S. Michigan Av., deal in expensive world class instruments. A $150,000 Fazioli piano in a window display is just one example.

Bob Berger, the building’s owner has no plans to shut down during the summit, but he’s among the many concerned downtown business owners.

“Is this going to be like Seattle? We hope not,” Berger said, referring to the 1999 World Trade Organization conference in Seattle, which drew violent protests, as demonstrators challenged police and destroyed property.

Arnette Heintze, the former U.S. Secret Service Special Agent in Charge in Chicago, who co-founded the Hillard Heintze security services firm with former Chicago Police Supt. Terry Hillard, said, “there has been an unfair characterization of issues 10 years ago in Seattle, and trying to associate that with what will take place in Chicago now.”

Heintze’s firm is advising City Hall on summit security measures. He said downtown businesses will soon be visited by law enforcement officials, to help them prepare.

“They will not close businesses down. They will work with them to facilitate their needs,” he said.

Some have expressed concerns that public transit into downtown Chicago could be limited, or shut down completely, during the summit. Heintze said he isn’t recommending that.

“I think public transit will be wide open,” he said.

The summit will be held on May 20 and 21, a Sunday and Monday, at McCormick Place. Bordered by few structures and a lakefront park, Heintze said the convention center is an easy location to secure.

He expects nearby Lake Shore Drive and the Stevenson Expressway will remain open, except for during periodic arrivals of the nearly 60 heads of state attending the summit.

Berger’s building faces Grant Park, the site of permitted protests. He’s added extra security cameras, hired an additional guard, and is ready to close the building if his tenants are threatened.

“If it comes down to it, we’ll tell them ‘Go home, stay home,’” Berger said.

Rolling road closures will be the biggest complication during the summit.As the roughly 60 heads of state are shuttled about the city, there will be occasional street closings. They are expected to not just visit McCormick Place on the Sunday of the summit, but to also venture into Chicago’s neighborhoods on that Monday.

–CBS 2 Political Producer Ed Marshall contributed to this report.