The illustration looks lovely, however, the realisation would probably have been more like Docklands Light Railway, which is elevated but not following the existing streets as per the illustration. There is a certain amount of wasteland that goes in the immediate vicinity of the DLR, which is a 'light' railway with the electric propulsion that was what they were looking for with the pneumatic system.
Elevated railways like monorails aren't more widespread because of the added expense around elevated track and especially elevated stations. Somehow, you've got to get folks up and down from there. I'm glad because they are pretty unsightly.
All costing I've seen for elevated tracks is actually significantly cheaper than at grade or underground options. I used to be on my local government and worked with the state government on a number of transport projects so I can't cite sources directly. This website has some comparisons, but obviously is biased towards monorails.
https://www.monorailsaustralia.com.au/
If you look at countries such as Japan that asides from population density have a very relaxed attitude to multifloor buildings having entrances at different levels you can see successful elevated railway implementations because the stations are integrated to existing large buildings such as malls, hotels & commercial offices.
One thing I've noticed in Sydney was people don't tend to look up if their not expecting something, so in Chinatown and Koreatown (We don't really have a Japantown yet but Sydney Central Park is getting there) buildings have advertisements on the other floors to let people know they are upstairs. In the rest of the city you can walk past a building and have no idea who the tenants are on the other floors. This also stopped Sydney from noticing the (in hindsight) blatantly obvious, almost Jetsonesque monorail stations right above their heads.
with an overhead railway you have the problem of getting people up and down from the platform, and it's only marginally less intrusive to the rest of the public realm than a ground-level railway is.
with an underground railway you do still have the same problem of getting people up and down to the platform, but you have the advantage of the railway being completely out of the way of anything else.
An atmospheric railway would not be silent. Steel wheels on steel rails make a lot of noise, especially before the development of continuous welded rail, and also when without the dampening effect of being on the ground.
No, the whole point is that it does not: the arcades would be connected to the buildings, providing a roof which people could under lengthwise.
This is important, because that meant, as the article says, that the building facades had to be rebuilt all the way through.
And this was a major reason for a no-go for the project.
Seattle Monorail runs on a track that is supported by wide pillars, not an arcade. You can't walk length-wise under it, the pillars are in the way. But the pillars mean that it does not need to touch the buildings it runs next to. It can (and does) go in the middle of the street.
Wow, now this really is a forgotten gem of history. They raised every building in Chicago on jacks, with people still inside them!
"One patron was puzzled to note that the front steps leading from the street into the hotel were becoming steeper every day and that when he checked out, the windows were several feet above his head, whereas before they had been at eye level."
