CHANGE: Hard-coded 50km/h city speed limit replaced in all places by the speed limit of the city road set in the pakset for the current era
CHANGE: Cities will only adopt roads that already have pavements/sidewalks (i.e. those which have neighbouring buildings)
CHANGE: When cities construct buildings near existing roads, always take them over and add sidwalks/pavements (thus reducing the speed limit), but retain the existing road if it is superior
CHANGE: Building a road over existing city road does not remove pavements/sidwalks
FIX: Upgrading a road in a city would always cause its speed limit to be reduced to 50km/h even if it was not near any buildings