Changing our cities has happen. For example a big chunk of the Wellington CBD could be made off limits to cars from say 11pm Friday to 11pm Sunday especially from Lambton Quay along Willis Street to Manners Street then Manners St to Taranaki. This would open the CBD to bikes, scooters and pedestrians and bring the city to life.
Never been there before myself but from all the maps i see every day it would look like it would make a lot of sense.
Maybe a reduced speed limit like 20KPH CBD wide with a tarrif so peple could still use the roads to say pickup an appliance but at their disadvantage so it makes public transport logical.