HoMM3 HD is a mod (add-on) for the game Heroes of Might and Magic 3.

Why is there a choice of road type in Multiplayer? Is it necessary? How often do you select slow/medium roads?
Maybe just an option 'paved (fast) roads' is needed?

Well, usually all templates are played on medium roads. Jebus Cross on fast roads.
It's also very strange that no one plays on slow roads, even though slow roads are my favorite. :)