Could be fixed with a few maintenance spells that slow down the movement of enemies when they enter your territory.  If you want to have roads, then you can decide if you want to manage the spells to slow enemies down.   That or put a few scouts on the road leading to your city.

As has been hinted at in here there in this discussion, there should be plenty of overland spells that players can use (and ai) to hinder and control the map. We have three pretty good ones at the moment and we can definately use more. The major problem we have with these spells atm is they require the target to be within your zone of control. I don't recall off the top of my head if the zone has been nerfed or increased lately, but in terms of spellcasting the zones are far too small. This is especially true since early on you can use a movement 2 stack on a road to get 4 or more movement point (depending on the road quality) so you can stand at the edge of a zone of control and then suddenly zip in at the beginning of your next turn while taking full advantage of the road to rush in without the opportunity for the ai to cast spells on you, not that it does.

    Likewise, because of the odd order of troop movement, when there is no road and the ai moves right beside you city, there are times when you think you should have the  chance to toss spells at them, but they move before you do so the enemy army moves into attack as you move your heroes into your city to defend, or move to attack the enemy stack itself before it attacks your city, but the order of movement is against you and your hero ends up moving into the city after the fight is over. Which is weird.

It's teh same situation when you are 1 square away from a monster, say a bear, with your early game sovereign, and logicially, you should be able to move away from the bear. You click to move your stack, and then the bear moves into the square you just vacated and a fight starts resulting in the bear tearing you limb from limb and mauling you to death, along with your hero and militia units. Gotta love that early game bear of death.

Now if we are looking at roads historically, you would have checkpoints such as toll booths and forts that would control movement in an area. Anyone who eneters these zones would get attack, hence ZONE OF CONTROL. Imagine your little peasants moving around, gathering resources and exploring and finding new stuff for you in your territory. This is your zone of control. It is your precious. They can't have it. They enemy ai's are not allowed to touch your roads, they are your precious. The enemy ai should not be allowed to walk right by your outpost and destroy your mine. It is your precious. If you don't go where i allow you to be you shall be smitten with flame and ice and stone. But only if i can see you, or your not running faster than i can see on my roads. (insert witty remark here but daughter pointed out my typos - so i forgot) probably a precious comment i have no idea.

It isn't that big a stretch to assume that taking roads through your own territory where you can resupply from villages along the way would be faster than taking roads through enemy territory where the enemy would obviously be doing everything they could to destroy bridges, bring rocks and trees down on the roads, etc. We're making far bigger stretches of logic elsewhere in the game than this would be!

It also isn't a completely new and scary idea. Various TBS games including Civ4 had systems where you couldn't make use of roads in enemy territory and it worked well towards hindering offense. This is generally a good thing because in games where players take turns if movement is easy then offense is much stronger than defense. (the defender has to defend everywhere while the attacker can choose from a wide range of places to attack).

It's up to Stardock to decide but I would be for making roads not work in enemy territory.

Final Word:  (Direct Quote from Derek Paxton's v0.915 Changelog)

       + Units don't get additional movement from roads in enemy territory

Good Outcome !      

Silly game mechanics with no frame of reference ruin immersion.

Fantastic mental picture

Sincerely
~ Kongdej

Armies moved slower in enemy territory in real life. This was mostly because of problems like extended lines of supply and unknown terrain.

Since we dont have supply in this game, disallowing road use for invading armies simulates that slowdown.