A car-free city or carfree city is a population center that relies primarily on public transport, walking, or cycling for transport within the urban area. Carfree cities greatly reduce petroleum dependency, air pollution, greenhouse gas emissions, automobile crashes, noise pollution, urban heat island effect and traffic congestion. Some cities have one or more districts where motorized vehicles are prohibited, referred to as car-free zones.
Many older cities in Europe, Asia, and Africa were founded centuries before the advent of the automobile. Many continue to have carfree areas in the oldest parts of the city – especially in areas where it is impossible for cars to fit, e.g., in narrow alleys.
In 2006, Abu Dhabi's redevelopment agency released the masterplans for Masdar City, designed to be a highly sustainable and fully planned city. The plans were also focal on ground level street spaces being pedestrian only spaces, with no personal motor vehicles being permitted within the city confines. Thus, aiming to be a walkable city, and using fully electric, and autonomous, personal rapid transit for traveling greater distances.
As part of the city council's 2014 Urban Mobility Plan, Barcelona has implemented its 'superblock' designs, wherein pedestrian-only spaces are created, encompassing the interior streets of nine city blocks (four, in some outer suburbs).
Some proposed car-free cities are government planned and funded, such as Masdar City and Tianfu New Area near Chengdu in China , while others are planned privately such as The Venus Project designs. In places without roads there is no need for a road tax.
The direct benefits of car-free urban designs are mainly in mitigating the negative effects found in many cities, such as poor air quality from pollutants as a result of the combustive process used in many motor vehicles, noise pollution and ground vibrations from the engine and vehicle use, and reduction of the urban heat island effect. Another would be the obvious reduction of pedestrian and cyclist collisions.
The indirect benefits are predominantly to do with the revitalisation of the space triggering encouragement for people to be more physically active, whether to commute, exercise or for leisure. This in turn can help lessen the implications that come with mental health and the segregation and isolation caused by car dependent societies. Another obvious indirect effect is an enhanced sense of community, or belonging, as well as perceived 'ownership'. This can mitigate sociological tension, and further enhance public wellbeing.
Braess' paradox states that "for each point of a road network, let there be given the number of cars starting from it, and the destination of the cars. Under these conditions one wishes to estimate the distribution of traffic flow. Whether one street is preferable to another depends not only on the quality of the road, but also on the density of the flow. If every driver takes the path that looks most favorable to him, the resultant running times need not be minimal. Furthermore, it is indicated by an example that an extension of the road network may cause a redistribution of the traffic that results in longer individual running times."
Car-free designs limit transport options. Cities vary in their degree of automobile dependency, and urban structure tends to follow a concentric zone model. Thus, people living in suburbs and exurbs might gain little benefit and lose convenient access to the inner city, in redevelopment schemes for central and wealthy residential areas.
An existing city can be made a car-free city by strategic closures of streets and squares to car traffic and reserving them to exclusive pedestrian use. This is often done in practice by means of physical barriers (i.e. traffic bollards). These barriers can be fixed or movable (in which case, some traffic -i.e. public transport, vans which need to restock outlets in towns, garbage trucks, ...) are still allowed to pass but personal car access remains barred. Opening and closing of such barriers is often done manually, through an electronic pass but can even be done by means of ANPR camera's connected to the barrier system. Often, parkings are created at the outskirts of the city to allow people to park their car there, and/or take an alternative means of transport into town ("park and ride").
After the closing down of streets and squares to personal car traffic, a pedestrian and bicycle network gradually emerges and joins several parts of the city. Similarly, prompted by the same need to avoid conflicts with car traffic and enhance pedestrian movement, pedestrian networks have emerged below street level (underground city) or above road-level to connect large downtown areas as in the Minneapolis Skyway System. For new areas on the fringe of cities or new towns, two new complementary ideas have emerged. The concept of Filtered Permeability (2007) and a model for planning towns and subdivisions - the Fused Grid (2003). Both focus on shifting the balance of network design in favor of pedestrian and bicycle mobility.
The city of Venice serves as an example of how a modern city can function completely without cars. This design was unintentional as the city was founded over 1,500 years ago, a long time before the invention of the automobile. Visitors who drive to the city or residents who own a car must park their car in a carpark outside of the city and then proceed either by foot or train into the city. The predominant method of transportation in the city is by foot, however motorised waterbuses (vaporetti) which travel the city's canals are also available.
Other examples of carfree places are Mackinac Island and Paquetá Island, where cars are banned and the main transportation is by means of horses, bicycles, and boats.
The design for Masdar City adopted a car-free philosophy as part of its fundamental basis of being an eco-city. Personal cars are eliminated from the street spaces, in favour of a walkable city design, and use of its autonomous personal rapid transit network for public transportation over greater distances. The Great City, in China, is another example of a newly-developed city, designed with the fundamentals of a car-free city in mind.
Several cities are partially closed to vehicular traffic. In Ghent, Belgium, the entire city heart, 35 hectares, is almost car-free: public transport, taxis and permit holders may enter but not exceed 20 km/h. In Strøget, Copenhagen, there is a large downtown car-free shopping area. In Oslo, cars are completely banned in some streets, and it also removed more than 700 curbside parking spots and replaced them with bike lanes, plants, tiny parks, and benches. It sees this as a major step toward a vision of a car-free city center.