Of course it's not quite that dramatic, it's the centre of the city which has banned cars.
They stopped cars crossing the city and got rid of street parking, as people looking for a place to park is what causes the most congestion. They closed all surface car parks in the city centre and opened underground ones and others on the periphery, with 1,686 free places. They got rid of traffic lights in favour of roundabouts, extended the car-free zone from the old city to the 18th-century area, and used traffic calming in the outer zones to bring the speed limit down to 30km/h.
Main grumbles are insufficient public transport and congestion at the periphery.