If you're planning to go anywhere on Metra from 5/19 to 5/21, you'll want to be aware of security measures that will be in place, including the following:
Metra has implemented a wide range of safety measures during the NATO Summit. Passengers may see an increased law enforcement presence and K-9 units. In addition, the following safety measures apply to riders of all Metra lines during the three days (May 19, 20 and 21) of the summit:
Riders may be subject to search and/or screening before boarding or while en route.
Riders may carry only one bag not exceeding 15 inches square and 4 inches deep. Boxes, parcels, luggage, backpacks and bicycles will not be allowed on trains. Banned items cannot be stored at Metra stations. They must be removed or they will be disposed of.
Riders may not carry any food or liquids on the trains. This includes coffee and other beverages.
Riders may not carry any type of tools, pipes, stakes, wood or weapons, including pocket knives and pepper spray, on the trains.
Law enforcement personnel must identify themselves and present their credentials and any weapons. Security guards will not be allowed to carry any weapons onboard.
This means that, if you would normally use Metra to connect with a CTA train to fly out of O'Hare or Midway, or get you to Amtrak for travel, you may be out of luck on Metra due to luggage restrictions.