There might be more exciting or relevant thematics at the moment regarding the recent big update, but I still want to bring this up, since it has been bothering me (and everybody else i have talked to) for a long time and gets more annoying each day.
What I am talking about is, as stated in the title: the cart mechanics, or as I like to put it: the by far worst and least fun aspect of the game.
In the following I'll give the reasons why i think the cart system needs a dramatic overhaul and will make suggestions on what it could look like.
1. Time consumption.
The movement speed of the carts in combination with the location of the mine/mill relative to your castle leads to absurdly long travel times. This leaves you with two unpleasent options: a) just send it and risk it getting stolen (which in my experience happens way too much even on close to one-colored servers) or b) escort it and mindlessly stare at your screen for 1 to 15 minutes, which in my opinion and experience is just annoying.
2. Cart robbing.
Or more specifically cart robbing while hiding in the capital, which in my opinion is plainly stupid, since there is no way to retaliate, and if you arrange it cleverly (spending all your energy before you go robbing) you can't even be punished by getting dueled.
3. Restrictions on cart robbing.
Or rather: there sems to be no working systems on them. While some people can't see any/ only close to own power level player's carts, others can see every single cart (and usually try to rob them all). To give an example: on my main server i can see only stronger player's carts, while on another server my low level account gets robbed by equally weak people as well as by people with 10 times my power rating, while i cannot see their carts.
Now to my suggestions for changes:
For me personally (and a lot of guild mates) the most bugging part is people in the capital stealing your carts. My suggestion here would be to add a personal (only the robbed person, not the entire guild) revenge button, which would be the easiest way to improve the cart system. This would also ease up the escorting situation, since people would have to think twice before robbing your carts, because they can't just hide.
Another way of improving the system could be allowing carts to be escorted to the capital or closest city your guild owns instead of to your castle. This would shorten escort times and make escorting a less drawn out, dead time, no-fun job, while also rewarding large scale organization further.
While those two options are rather minor and easy changes a complete overhaul could and should be considered as well. A possible system I came up with for this looks like this: On your own territory carts are unrobbable and need no escorting, on neutral ground they can be robbed and on other kingdoms' territories a "toll"(X% of your carts value) must be paid whenever your cart passes a city (which goes to the cities owners), or you have to fight a member of the city's guild before you can pass, etc. This wouldn't just make carts more interesting and less of bothersome chore type of activity, it would also redefine the value of cities and their locations and open up new macro strategies regarding city occupation and could lead to more interesting map coloring structures.
Anyways, the cart system as it is now lowers the fun and enjoyability of the game a lot for a large amount of players and should be considered a somewhat high priority for changes.
Feel free to voice your opinions about the cart system and add your own suggestions!
TL;DR: Current cart mechanics are lame, please make them more enjoyable and less of a necessary duty nobody is happy to do.