How accessible will the city be during DNC?

CHARLOTTE, NC (WBTV) - The Secret Service is by no means ready to share its plan to keep President Obama and you safe during the DNC.

But seasoned security experts like Ross Bulla can give us an idea of what to expect.

"You definitely won't be able to bring your car within certain zones," he says.

When preparing for big events, security professionals start by drawing zones around the three blocks surrounding any important venue.

"That changes based on what's called a blast and a plume analysis. They basically determine through modeling how far a weapon of mass destruction may have an impact. That moves that three block radius in or out," Bulla explains.  "High rises can certainly block that affect and bring the zone even closer. But within certain zones only vehicles are screened. And then the closer you get to the property, vehicles aren't allowed and persons are screened.

"People worry about the perimeters and streets being shut down 24 hours. Well, past history tells us that's not always the case," Bulla says. "There will be certain primary roads even within that zone that will be open during morning rush hour, and might be closed during evening rush hour."

Public transportation, of course, will be affected too.

"The concern with the stadium is that it's an open air environment so you expand that perimeter and there's a rail line right next to it," Bulla says. "During the day of, and probably days or weeks prior, they will shut down entirely or regulate rail transport, most certainly hazardous materials."