FEEDBACK > TRANSPORT > UPGRADES (no downgrades)
Just like it is currently possible to increase / descrease the amount of advertising at a city -- it would be awesome if we also had the ability to "Downgrade Transport" -- and get back some of the value invested.
This would be useful for balancing the production vs delivery vs demand ratio -- because it is a time dependant property, which is also affected by the speed (and amount) of items delivered. (Sometimes you need to slow down the delivery.)
But it's nice, that the Transport Upgrade is a single-time cost vs increased cost in time.