Well, I just found this:

http://orbis.stanford.edu/

It's an interactive map that shows precisely how much time it took to travel on roman times. it includes a bunch of different ways to travel (on foot, on horse, a marching army, on boats, with a cart, etc.), it also includes prices and alternative routes depending on whether you want to travel fast or cheap.

TL;DR: It's a roman empire travel planner.