Transport is an essential aspect of any organisation within Chronicles of Elyria. It affects the movement of trade, movement of armies and movement of people. Therefore it is essential to have a robust transport system within the Duchy of Feann. It is not yet known what elements will be handled at a kingdom level and what elements will be handled at a duchy level. For this text, I will assume that major roadways connecting the different duchies will be handled by the kingdom and that more localised roadways will be handled by the duchies.
The first goal of the duchy is to make sure that each town or city is connected with minor roads. This is likely to mean unpaved roads at first with major trade routes being prioritised for paved roading depending on how much money is available to invest. It is important to note that it is likely that most of the duchy will be using unpaved roads for a reasonable length of time as it is expected that having paved roads will take a fair amount of money and time to implement.
Once the major trade routes have decent paved roads, then roads will be upgraded according to need. It is likely that most minor trade routes will remain unpaved for an extended period and will only be upgraded if the road becomes impassable (say during winter).
Depending on the political situation then it might also make sense to prioritise military routes (say from the capital to the border forts) to make sure that the duchy is well defended. The military will have to take priority over trade routes as a defenceless duchy will allow criminals to steal from trade routes and also open up the border of the kingdom to the risk of attack. The routes military forces will take will have to be discussed between the duke, the counts and the barons. Resources will be allocated to ensure a strong defensive position along the external border of the duchy.
If the Duchy has a coastline, then it is important to also make use of naval transport. The Navy could also save us money on road development as we could ensure that large-scale trading primarily happens via sea rather than by road. Having said that if you are trading by sea, you'll also require a navy to protect trade vessels from hostile forces such as pirates or enemy kingdoms. The navy will initially work on securing trade routes, and then trading vessels will be built once the sea routes are secured by military vessels.
Rivers are also an important aspect of transport and of course they will be used to quickly move goods between towns since it is likely that towns will want to establish themselves near a river in order to help promote trade by the river and also by sea (assuming seafaring vessels can access the river). More information on rivers will be discussed once we know where the Duchy is going to be located and the natural features of the Duchy.
The funding of major roads will be handled by the Duke. Smaller major roads will be handled by the Counts (for instance a road which connects two counties), and small local roads will be maintained by Mayors / Barons. There will be a public budget allocated to road transport which will be used to keep the major roads open at all times. Also if smaller roads have any problems then Counts, Mayors or Barons can put in a request for public road fund to pay for urgently needed repairs. This money is not a gift though and will need to be paid back. The exact time frame for repayments will be discussed on a case by case basis.
Maintenance of roads will be handled by the person that pays for their upkeep. Thus for major roads, the Duke will maintain them. For the county to county roads the two local Counts will share the maintenance burden, and for small local roads, the Mayors and Barons will deal with maintenance.
The only time that this is going to be different is if the military is involved. In such a case road maintenance will be handled by the Duke and the Barons directly since we will need to ensure that the military can move around relatively unhindered.
The building of roads is a difficult question and will likely revolve around how important each specific road is. It is quite likely that the Duke will maintain a maintenance crew who will keep the major roadways open at all times but for small local roads which have an impact on the local town then the Mayor or Baron will be in charge of maintenance. Like the maintenance section above the only time that this is not the case is if the road provides an essential military function in which case the Duke and Barons will be in charge of maintenance.