and goes to the center of downtown Chicago. No,the private disruption is not worth the novelty and the travel time saved even if paid for imo
https://www.transitchicago.com/airports/

I met with the Chicago Infrastructure Trust about this last year. The goal is to have both an express service (targeted towards business) and a local service, similar to London and Tokyo. The underlying goals of the Musk project were to keep the fare equivalent to a taxi trip.

If Elon musk and his demographic don't mind rubbing elbows with the unwashed masses, they can take the Blue Line for $2.75.

Maybe they can buy Northerly Island and rebuild Meigs, but just make it a helicopter pad.

It takes a while to get downtown from Midway, too.

...making it less practical for Airport service.

And they often carry a lot of luggage with them, crowding the cars for regular commuters. But it's only for about 40 minutes if you get on near the Ohare end. You stand for a bit. It's no biggie. I think there may be more ohare riders because the cost of a cab, or an Uber even, is more than it's worth to many.

Plus I think a billion is optimistic. Chicago has a lot of already in place underground infrastructure. There is no virgin right of way to be had.

And not everyone heading to O'Hare starts downtown.

It's a cool idea, but recent (2014) estimates for digging a tunnel 1/3 the length (from Staten to Manhattan) were about $1.75B. So you're talking potentially $5B + just for the tunnel. Elon Musk might be able to do it cheaper, but 20% of the cost is optimistic enough to warrant skepticism. And the costs only go up for every station you create. I don't think you could get away with making an almost 15 mile tunnel without at least one intermediate stop--probably at Logan's Square and with a connecting pedestrian tunnel to the Blue Line.

I think Rahm's support of the project was rhetorical for the most part.