Nice looking map!

One thing you might consider is that the yard areas between city buildings are more likely to be bare earth rather than grass, due to people trampling them, throwing out chamber pots, overgrazing by various animals (goats and chickens) and a lack of sunlight. There might be little vegetable gardens here and there, of course...

You might also consider adding some non-paved paths where people are likely to make shortcuts, for example for carts and oxen with plows to follow out to the fields.