Hi again, my son and a friend are flying up to for the concert possibly staying in Downers Grove. Someone said there is an express train? into the city. Are you familiar with this train and how late it runs? Also if they are commuting back to the burbs what would be the latest "safe" time. These are two teens who just graduated HS. Any other words of wisdom. This is their first time up without parents. Thanks as always for your help.