Looking for feedback on this.
How much would 1 mile of paved road probably cost?

Floor/Roof, flagstone or tile (10’ x 10’)* 40gp and Extrapolating from Corridor, dungeon (10’x10’x10’, hewn stone walls, flagstone floor) 500gp. = 65 gp.
So i would use something in between, say 50 gp per 10x10, including build cost but not accountaing for terrain…
so 1 mile = 5,280 feet = 26.400 gp for a 1 mile long, 10’ wide road ?

Quick and dirty calculations based on some roads built in the Auran Empire campaign:
Material cost of paved road: 200gp/mi
Manpower costs: 25gp/mi (assuming 100 laborers)
With both scaling up based on modifiers (exotic paving stones, etc) which I unfortunately don’t have on hand.
You might need to hire an engineer as well if you don’t have one already on hand for your domain.
Construction time is 1 week per 2000gp in costs.
If I remember correctly, this was for a 5ft wide roadway.

Hey Marcus, I’m wondering why you guys used 2000gp per week instead of the standard 500gp per day that the ACKS rules use for buildings and whatnot?

The Auran Empire campaign preceded ACKS, so not everything we did initially is how we finalized on doing it…

Right. I decided to increase it to 500gp per mile instead of 200gp per mile just to keep it easy math.
This brings up an interesting question I hadn’t thought about before though.
Are laborers fees and whatnot assumed to be included in the cost of building castles and buildings? Or, should that be an added cost that doesn’t impact the build time?
Should the Judge just guesstimate how many laborers (and other specialists) are needed for each project? Or, is there a guideline?

Labor fees are assumed to be included in the cost of building castles and buildings, so you needn’t track it.

After some additional research I was able to source the cost of standard Roman roads at 10,000 sesterce per mile. A sesterce is 4 copper asses, and in the assumptions of ACKS, 1 copper ass is equivalent to 1 copper piece. Therefore the cost of a road is 40,000cp per mile, or 400gp. A standard Roman road was 8’ wide.
The following can be considered an official rule:
Road, leveled earth (8’ wide, 1 mile long) 100gp
Road, leveled earth (10’ wide, 1 mile long) 125gp
Road, gravel (8’ wide, 1 mile long) 200gp
Road, gravel (10’ wide, 1 mile long) 250gp
Road, paved (8’ wide, 1 mile long) 400gp
Road, paved (10’ wide, 1 mile long) 500gp
Multiply the base cost of the road by the terrain movement multiplier:
Desert, hills, wooded areas x3/2
Thick jungle, swamps, mountains x2
EXAMPLE: Quintus wishes to construct an 8’ wide gravel road through 4 miles of mountains. The cost is (400gp/miles) x (4 miles) x 2 (terrain) 3,200gp.
Construction of roads can be considered investment into a domain for purposes of attracting peasants.

Wow. That’s far more than I expected! Thanks, Alex!

Roads are way more expensive than most folks realize. If you already have a level and prepared base for a road, RE-paving a mile of roadway 8’ wide would over \$100,000 today. Building from new might be several times that.
Another way to look at it is that if you want to employ 100 laborers building a mile of road eight feed wide, each laborer must level, fill with gravel, compact and lay flagstone for 425 square feet of road area, at an good depth assuming Roman Road construction - which would be wider than eight feet for main routes. So, our eight foot wide paved roman road requires each of 100 laborers to remove and rebuild about about 850 cubic feet of earth, assuming the fill materials and metalling (surface) are coming pre-purchased and the ground is suitable.
Total extrapolation: If he can dig out and re-build one cubic foot every thirty minutes of labor (a wild guess but I think not far off), the total exercise will take 425 hours for each laborer. That is 14 weeks assuming ten hour days, six days a week. Just to build one mile of road. This is why good roads are so expensive.
Of course, you can get a lot more than 100 laborers involved, and also many roman roads were obviously built up with continual work over centuries, but if you want to simulate that then you need a pretty hefty maintenance fee per mile of road to represent continuous ongoing work.

~650 ft long, 20 ft wide, ~\$100,000

Brianleet, thanks for the additional details. They seem to be in the same range as I saw from other sources.
A laborer in ACKS costs 3gp per month, so 100 men laboring for a month is 300gp.
If we assume 1 cubic foot per 30 minutes, then a road would cost (100 laborers)(3gp/laborer/month)(14 weeks)*(1 month/4 weeks) 1,050gp.
If we assume 1 cubic foot per 15 minutes, a road would cost 525gp.
If we assume 1 cubic foot per 10 minutes, a road would cost 350gp.
If roads were 10,000 sesterce per mile (per my email above) then we’re in the ballpark at 1 cubic foot every 10-15 minutes.

Sorry to resurrect this excellent but old topic.

I wondered if the cost of the road would be added to the cost of the stronghold for monthly ongoing maintenance purposes?

Or should it just be assumed to happen and forgotten?

Brennall, you can either consider the road part of the stronghold (a military expense) or part of the domain (an investment).

If you consider it part of the stronghold then it will need to be maintained (per stronghold upkeep), but by adding to stronghold value it will increase the size of the domain that the stronghold can secure. These would be "military roads".

If you consider it part of the domain, then it would not need to be maintained, and it would attract new peasants. But it would not help the stronghold's value, so the maximum size of the domain would not be increased. This would represent a lord commissioning roads, but then handing them off to private merchants and so on to run.