New York pedestrianised sixty blocks of road, and Paris is banning cars from 400 miles of its streets. Today, Cardiff also takes part in World Car Free Day - by banning cars from just one city centre street.
Park Place in Cathays is traffic-free until midnight tonight. Some people on social media have responded positively to the capital's first car free day - but there has also been a lot of criticism at the decision to only make on street car-free.
Others have complained that the closure of Park Place to cars has caused build-up of traffic and delays in other parts of the city.
Others have reacted more positively:
The event has attracted many stalls and exhibitors along the usually busy street including Cardiff University, Sport Cardiff, New Adventure Travel, South Wales Police, Cardiff Council Road Safety Team, Newport Bus, Arriva Trains Wales, Pedal Power, Stagecoach, Living Streets, Dr Bike, Travel Line Cymru, Sustrans and Cardiff Bus.