Roads, flags and carriers

Newcomers build roads. Experienced players build flags, and let the roads follow. Here is why.

A road is a chain of segments between flags

Every road you lay is cut into segments, and each segment runs from one flag to the next. A flag can sit at most every second node along a road, and one carrier is assigned per segment — not per road. A single long road with few flags therefore has few carriers on it, each walking a long way; the same route with flags placed regularly has more carriers, each with a short beat.

Flags are also where wares wait. A carrier does not run a ware from the producer to the consumer; it moves it one segment, drops it at the next flag, and the carrier on the far side of that flag picks it up. Goods leapfrog down the chain. That is why a queue of goods piling up at one flag is the clearest possible signal of where your network is too thin.

A flag decides what moves next

When several wares are waiting at a flag and a road is free, the flag picks one — and it picks by transport priority, not by arrival order. Each ware type has a default slot in that ordering, and the flag takes the most urgent one waiting. This is the mechanism behind the classic failure mode where boards pile up at a junction while the building site that needs stones starves: the flag was doing exactly what it was told.

The donkey upgrade

Carriers keep score. Every carrier measures how much of a fixed window it actually spent working, and a plain human carrier that was busy for at least most of that window upgrades its road: the segment becomes a donkey road, its two flags become large flags, and a pack donkey is ordered to fill the segment's second carrier slot.

Nothing else in the game ever produces a donkey road. It is earned by traffic, which means the upgrade appears exactly where your economy is actually straining — and it is a reliable way to read your own network. If a road has not gone donkey, it is not the bottleneck.

Waterways

A road drawn over water is a waterway, worked by a boat carrier rather than a human. Waterways have a maximum length — a lobby option, with "no limit" among the settings — and the road-building UI cuts a route that would exceed it rather than letting you finish an illegal one.

Practical advice

• Flag the long stretches. Any road where you can see a carrier walking without cargo for several seconds wants another flag.
• Junctions want space. A flag with four roads meeting at it is a single point every one of those segments has to hand off through.
• Read the pile-ups. Wares waiting at a flag are the network telling you where it hurts; wares waiting at a producer mean the road out is missing, not slow.
• Let the donkeys tell you. Upgraded roads are a free heatmap of your own trade.