One option to improve the road connectivity would be to extend it beyond the point where it touches a lower level mill and a redoubt all the way along centrally. To do this, you'll have to make that central section wider by 1 tile, so that the road runs between these pairs of buildings all the way in: catapult and command post, ballista tower and mill, catapult and redoubt, balista tower and redoubt, market and stable.
The next level of improvement would be to make another similar centrally running road, perpendicular to this one at the center.
Cheers and happy gaming!