I was just wondering if at a certain point a PC can outrun a black horse. I ask because it would be nice to eventually be able to travel without my mount without much hassle. I find a horse a bit of a burden, but it does get me places faster.

I would also like to know at what point can you fast travel faster without a horse rather than with one. I read somewhere the game uses your horses walk speed, and not their running speed in the calculation (although maybe they use your walking speed when you are on foot). I know that if you max out athletics and speed you can fast travel faster without one, but I want to know at what point it becomes even just a little faster so I know when to ditch the horse without having to get to 100 speed and athletics, and no I will not buff my speed and athletics for one second before traveling to achieve this. I feel that is kind of cheating.

I don't know the fast travel formula, but I do know that if I cast a fortify speed spell on me, I'll get there quicker during the fast-traveling. My current character has an Athletic skill of 79, and her Speed is at 70. She can easily outrun a black horse.

You can outrun horses pretty quickly. I think that Niles started to outrun horses around 65 speed and athletics. The fast-travel formula is weird, and I don't think that it matters if your are on horse vs. on foot before you start to fast travel. It'll probably always be faster to sprint to locations than it will be fast travel from a game-time p.o.v. It depends on how far you wnat to stretch the map. Can run from Leyawin to Anvil quicker than fast travel.

Walking and running speed is also affected by race. Your stride is proportional to your height, so an altmer moves faster than a bosmer, for instance.

I enchanted an entire set of clothing with fortify speed, and just whizzed everywhere - can't remember precisely how much my speed was fortified by, but it was a lot and took next to no time to run everywhere. I had no idea that speed affected fast travel though - although why I might assume it wouldn't I don't know!