Sometimes while doing the escort quest, the Estate to which you have to deliver the noble is in the enemy territory (I believe this is more frequent when the inn as near the enemy borders.
What's annoying about this is that you have to declare war on the AI to complete the quest or you are kind of stuck with a noble moving as slow as a turtle.
So a suggestion would be to have a diplomatic treaty (such as open borders.) so you can move about a bit more. 
