Ok, so I assume you are talking about this sort of thing.
https://www.reddit.com/r/worldbuilding/ ... s_walking/

In short, I'm seeing this.
1) In the style of an ultra-marathon, a human is possibly faster than horses over very long distances. Spear chuckers
2) When you add typical weight for travel, such as 50-150 pounds of armor, food, water, and so on, a human will be slowed down way more than a horse. It is much faster to take a horse over any distance.
3) For typical travel in the Roman empire according to the people at Standford, a human was 30km/day and a horse was 56km/day.

Reddit has actually been fighting about this for years, and while Orbis is definitely the one outlier for horse-based distance (outpacing other ancient and modern claims)
https://www.reddit.com/r/AskHistorians/ ... e_average/
It's not the only one out there. It does have a lot of work behind it, but it doesn't seem easy to really trace.

One thing that does seem true historically is that a lone rider on a horse, without exerting the horse, will go a bit further per day than a man on foot. This is definitely true if there's some packs to be carried. Even if Orbis represents an extreme claim. What's true of adventurers? Generally adventurers in D&D fall into one of a few categories:
1- Young healthy characters accustomed to moderate labor and walking, with moderate supplies and weaponry. These characters don't walk so much that they would be unable to engage in combat, something that a traveller on a Roman road wouldn't be too concerned about.
2- Similar characters all mounted on horses.
3- Similar characters with a pack mule or a horse-drawn cart or similar.

Then there's stuff involving greater magic or technology- you could have all your supplies stuffed into a bag of holding, or have a mechanical horse that never tires, or everyone could buy griffins or something. The cart could be made to hover or the load could be lighter.

Finally, we have to accept that our carrying capacity is wildly generous- an average man can be laden with 150 pounds of stuff without any penalty, a riding horse 480 pounds, 540 pounds. A PC that used point buy or assigned his highest 15 to strength and then added +1 with his race is at 240, and your barbarian will soon not sweat a 300 pound load in moment-to-moment combat. With these assumptions, we are unlikely to see the rest of the model give benefits to horses for weights even where they are appropriate.

The general model for overland movement that we are using is on page 181 of the PHB. This gives us 24 miles a day, or 4 of these 6 mile hexes. You can go fast and have a -5 to perception checks and go 30 miles instead (5 hexes), or you can go slow and cover only 18 miles (3 hexes), which lets you roll stealth checks and force enemies to beat that. I've generally been giving you 5 hexes if you are in terrain where perception doesn't matter much (not every encounter is going to be gated on opposed checks), or 4 hexes otherwise, an automatic transmission for my fun resource-based hex grid, but I haven't ever done the 3 hex + stealth thing because you'd definitely need to ask for that. I'd actually prefer if you guys set the pace yourself. There's also rules for going beyond 8 hours- at the end of the 9th hour of travel, the team makes a DC 11 Constitution save, and a failure adds a level of exhaustion. 10 hours? DC 12 Con check. Each hour makes it harder. The first failed check normally stops the group- if Cyndra fails, for instance, camping clears it for the next day, but if they press on one more hour the DC only goes up by 1, but suddenly Cyndra would be making the check at disadvantage- and on a failure, suffers from half speed and 2 levels of exhaustion, which would definitely stop the group, and then the long rest still leaves Cyndra with one level of exhaustion for the next day.

Further, the 5.0 rules give us this, also on page 181:


Obviously, the PHB authors were either convinced by arguments that use athletic young men on a walk instead of averaged walking speeds (middle aged people carrying loads bring your average down to 18 miles per day on Orbis, the average walking speed), or simply didn't want to penalize groups without horses. Or maybe considered that roads were uncommon enough that they would simply use the speed for plains or something.
Six mile hexes are also pretty standard, which I'm sure went into having each of the table rows granting an integral number of six mile hexes, something I definitely want to keep.

Ok, so how do we want to model it?

Basing our argument strictly on realism, we'd probably end up with some number for adventurers, some other number for mundane foot traffic, and we'd have another tier for horses. Is the horse number higher than the adventurer number? I think I'd argue that they are really close, but I'm much more invested in what you guys actually want it to be. We are limited by neither the stock rules (which I always view as a starting point) nor the realistic historical horse (you guys have the Standard Horse, notable for how fast they heal broken bones, and for living a century, nearly as long as humans), so the rules should reflect something about that, right?

So I propose that if you guys are using, I dunno, call it Enhanced Mounts (which is all the horses for sale- humans brought excellent horses with them, and as such nobody created them later- and would also apply to any other zippy mounts you might acquire later), then how about a table that has one NEW row and enhances the existing PHB182 table to look like:



This seems easy enough to track, and provides a small but hopefully important bonus over the 24 mile (38.6 kilometer, 19.3 beatpace) walking speed listed in the book. A larger bonus wouldn't be out of line either, but I'd probably want the Standard Horse to instead have some ability to do better on his Constitution check if you force march him versus enlarging his range further.

I don't have much to offer here. You've obviously thought about this a lot more than most of us have, so I have no issue going with your proposed rules.

And we STILL have nothing aboot Hoverhorse.