Portions of Lake Shore Drive and Interstate 55, the Stevenson Expressway, will be shut down when world leaders converge on Chicago this month for the NATO Summit.



Intermittent delays and temporary closures will also occur throughout the weekend of May 20 and 21 in the downtown area, in the areas around McCormick Place and along Interstate 90, the Kennedy Expressway, between O'Hare International Airport and downtown, officials said in a detailed memo released Friday.



However, the entire Dan Ryan Expressway portion of Interstates 90 & 94 will remain open, as will the Stevenson to the Dan Ryan, Office of Emergency Management and Communications Director Gary Schenkel said Friday.



Parking restrictions will be in place in the areas surrounding McCormick Place, with some of them beginning Sunday, May 13, a full week before the event.



The Museum Campus will also be affected by the summit. The Alder Planetarium, Field Museum and Shedd Aquarium will be open on Saturday but closed Sunday. All parking lots on the campus will be closed Saturday at 5:30 p.m.



[Edit: The Adler Planetarium, Art Institute and the Shedd Aquarium will now close for the entire weekend. The Field Museum will remain open.]



Access to Willis Tower, the Chicago Cultural Center and the Art Institute of Chicago will also be limited to pedestrians at times.



If you're heading downtown for anything that weekend, public transit will be your best option. But even then, you'll want to plan ahead and allow for plenty of time.



Chicago Transit Authority President Forrest Claypool said the entire rail system will be open throughout the summit. And he said the parking and road closures will cause a "limited number of reroutes."



The CTA, he said, will have personnel out at "key points" throughout the weekend assisting commuters.



"We think the inconvenience will be minor, but we'll be prepared for any contingency," he said.



UPDATE: NATO to Delay, Cancel Some South Shore Line Trains

UPDATE: Metra Bans Coffee, More During NATO Summit





Download: NATO Road Closures, Transportation & Parking Restrictions