Uber has a kiosk on the Lollapalooza grounds - ChicagoNow (blog)

There are two entrances to the Grant Park festival. The Main Entrance is at Michigan and Congress. There is an additional entrance to the north at Columbus and Monroe. Second, know how you will be getting there and getting home. As always, public transportation is the best choice. Brown, Orange, Green and Pink riders can use the Adams/Wabash exit and then walk east to the Grant Park entrance. Red and Blue line riders will want to exit at Monroe or Jackson. If you are driving, plan your route. Balbo from Lake Shore Drive to Columbus is currently closed for Lollapalooza set up and will remain closed through Thursday, August 6. Balbo from Michigan to Columbus will close Wednesday, July 29 and reopen Monday, August 3, afternoon. Jackson from Lake Shore Drive to Columbus is closed until Wednesday, August 5. Jackson closures will extend to Michigan on Wednesday, July 29 and reopen August 5. Columbus from Monroe to Roosevelt will be closed from Wednesday, July 29, beginning... Source: www.chicagonow.com