[echevil]

I believe an express subway line can do a better job. Though the initial cost for building new infrastructure is high, it also have the other two benefits you mention: Bypass all ground traffic and being very predictable (in fact more predictable than flying cars as it won't be impacted by whether). Moreover it can carry much more people at much lower cost. The benefit of high capacity could probably compensate for the high initial cost.

If regular subway is not fast enough, maglev train like the one connecting PVG airport to Longyang Rd subway station can complete its 19 miles trip in 8 minutes, with a fare less than 10 US dollars, and it has been running for almost two decades.

[FabHK]

The question OP was trying to answer was not “what’s the best technology for this application”, but “what’s the best application for this technology”.

And I agree, I’m thinking of short shuttle services in extremely congested cities, such as São Paulo, Jakarta, etc.

Yes, they’d be better served by a good subway system, but good luck waiting for that.

[echevil]

I’m just saying, we need to find other applications for this new technology. If we just want to connect city center to airports I’d so much prefer that people invest their money on trains which is a solution that can benefit lots of people rather than a just a few riches

[lovemenot]

Trains are great, but they exist already.

For a technology to eventually become mainstream, usually it first needs to find a sweet-spot where operational kinks can be worked out. Think of Tesla Roadster.

It may add value if you could suggest a more suitable initial application than airport shuttle.

[romwell]

If the best application for a technology is better served by another technology, then what's the point to begin with?

[FabHK]

1. The new technology is in its infancy, and we expect it to get better over time.

2. External constraints prevent the better solution from being implemented for now.

[ghomrassen]

The original plan was to run it to the "city centre" at People's Square and then on to the other airport in town Hongqiao. The problem was expense, and for money to be a problem for the infrastructure-happy Chinese, you know its not economically viable for the majority of countries on earth.

[echevil]

The problem is not simply expense but whether the expense is worthwhile. Given Shanghai is already connected by a subway web, the benefit of directly connecting two airports with maglev is very questionable.

Maglev is just a bit extreme but more traditional subway systems are already super common across the world. The RER trains in Paris is exactly what I mean by an express subway system. It’s much faster than the other metro system in Paris simply because it has fewer stops.