Arterial roads leaving the centre.
District shares.
Civic landmarks near the centre: how many of each (a fraction is the chance of one more).
Downtown is a strip this many metres either side of the main street (the arterial through the centre), districts.downtown × radius long each way; 0 = a disc around the centre.
Tallest building, floors.
Surface of the side streets in the downtown core (null = same as elsewhere).
Population range of the class; a settlement's radius follows its population through it (log scale).
Radius range, metres, from the smallest to the largest population of the class.
Road rules of this class, over the roads defaults (your own roads input still wins).
Default street layout.
District rules of this class, over the districts.styles defaults (your own input still wins).
Road surface per road class.
What a size class looks like.