Chicago needs an express train to deliver passengers from O'Hare to downtown in 20 minutes or less, and Elon Musk's Boring Company will submit a bid.
According to the Chicago Sun-Times, the city is looking for interested companies to "fund, build, operate" a high-speed O'Hare airport train. The article explains:

"The city and the trust will consider 'potential corridors above or below surface level' to deliver express service 'at least every 15 minutes for the majority of the day' for fares 'less than' the cost of a taxicab or Uber ride to O'Hare.

The goal is to deliver express service that would whisk travelers between downtown and O'Hare in '20 minutes or less,' cutting travel times in half.

'A taxi ride from downtown to O'Hare could be $60. Ubers run around $40. There's a lot of room between the price of the CTA or parking to price a service in a way that you can make a lot of revenue,' said Deputy Mayor Bob Rivkin."