carrying stuff; using animals (horses and stuff); using animals to drag stuff (aaah, the wheel); inland waterways (commonly canals); trams/trains, lorries (trucks)

- i think the next could be a conveyor.

i'm imagining something like a machine that sorts letters by their postcode (zip), only much larger, with the items going directly to their destination. initially a single conveyor would allow items to be added at several points along its length, and could be collected at other similar points. it will handle most backbone delivery work, so would probably run from city to city near large, currently overwhealmed, motorways (freeways). for example, in england i might expect the first such conveyor to attempt to link London to Leeds, or Liverpool to Hull (look at a map).

i'm not sure what form this technology would take, so i'm open to ideas. it must be faster and cheaper than using a lorry. it needs to be clean, so probably power by electricity. also, its motion should never be interupted by items entering or leaving.