From #openttdcoop wiki
Flat Hubs (also known as Ghetto Style Hubs), are not a recommended hub design. However, they are useful in certain situations...
- When you don't have a lot of money (in the beginning of a game for a cashmaker)
- You need a quick hub
- You're short on space
- You need a temporary hub
- All of the above
It should be noted, that Flat Hubs are very prone to jamming, and should be used in low traffic situations only. The original Flat Hub is shown on the right. It was used in the 1950s of the Collective Transport game, and is something that is pretty much unique to #OpenTTDCoop.