While building roads through the wilderness i have come across what a friend called "Road Litter" where there are tons of road out in the wilderness, half of them going to the same place all made by different people.
I would like to suggest a highway system.
the highway system would work is that it would be a Kingdom based paving and/or building option. the highways would (idealy) require flat/low-grade tiles to be built on and be a 5x5 entity with no hit box, as they are intended to be walked/driven across. this would allow a roadsign and milestones to be placed against the Highway and have the path lead down the middle of the highway. This would allow anyone crossing an area to know that a road is intended to go through here. it would also allow for ease of navigation between villages while adding an infrastructure system to the kingdoms.
if we wanted to expand the existing roadbuilding option to this level as well, I would love to see a highway marker at each end of the road that used stone road signs as it's milestones. yes, it's expensive. it's kingdom level, it's supposed to be expensive. but the reason behind this is that it would allow smaller roads to be built off the main highway without having lots of little road signs dropped along the highway.
I'm still working on fine tuning this idea and welcome your feedback.