The London Post Office ran an underground mail rail with small trains from 1927 to 2003:

https://en.wikipedia.org/wiki/London_Post_Office_Railway

Here are cool mail rail photos from some urban spelunkers:

http://www.placehacking.co.uk/2011/04/24/security-breach-lon...

I very much enjoyed reading that placehacking article, thank you! :)

New York City had a series of tubes (pneumatic tubes, that is) connecting various post offices around Manhattan and even to Brooklyn.

http://untappedcities.com/2013/03/15/nycs-pneumatic-tube-mai...

I was going to say the destruction of it was spearheaded by the automobile companies, but I was confusing that with the fate of the streetcar system in NYC and elsewhere:

http://en.wikipedia.org/wiki/General_Motors_streetcar_conspi...

I'd also read that it was upended by the company supplying delivery vans to the postal service: General Motors.

They could sling a package across Manhattan in minutes, but to drive there, then as now, takes a lot longer.

Chicago had a similar thing: http://en.wikipedia.org/wiki/Chicago_Tunnel_Company

Maybe like a new 'physical internet' where it really is a series of tubes.

And it will probably be tapped by the NSA, too.

This is actually genius. A nationwide tube system feels like it would beat the pants of of trucking.

I'm not sure about narrower though -- maybe the "with car" design could be modified to have shipping containers placed on to the sleds?

I was thinking about what would a cheap scale demo still be useful for. If you built one out of 2 foot plastic pipe, you might still be able to have a market for parcel delivery systems and therefore make your money back off the prototype investment before you make a bigger one. Linking some hospitals would be a good starting point maybe.