The Transurban CityLink in Melbourne, inaugurated in 1999, is 14 miles long and links the most affluent neighborhoods with the downtown area and the airport. Offering faster travel times, toll highways are capable of determining the lines along which future expansion of the settlements will develop. Given their size, this type of privatised space, which is increasingly occupying the lands of the large conurbations, puts the very notion of public space into discussion.

Projects like the CityLink can become pivotal in determining the evolution of a city’s form because of the fact that they are structural and tend to set the agenda of what sort of urban space is being created for future generations. At issue is the future of public space itself, in its social, technical and aesthetic forms. This is true from the point of view of by-passing of traditional agora like markets and the parking-based streetscapes, to the further privileging of the super-regulated private spaces of shopping complexes, another cocoon for which the freeways is the link.

The creation of tollway spaces to travel from one area of the city to another contributes to the fragmentation of the territory: financial centres, luxury residences, shopping centres, and theme parks are the islands connected by toll networks that bypass spaces and populations in the archipelago of colonies found in major conurbations.

As we know, highway routes are not exclusively spaces for flows. They can also be sanitary cordons that separate affluent neighborhoods from the growth of slums.

In Istanbul, in the wake of a period of economic and political renewal, new settlements for the emerging class have sprung up. They offer ‘Western lifestyles’, social uniformity, comfort and security from crime, and refuge from the multiethnic, chaotic, polluted city. Esenkent and Bogazkoy are two postmodern-style settlements built west of the city, composed of luxurious apartments furnished with swimming-pools and gardens. They are separated by informal villages with houses constructed willy-nilly along the highway routes that mark out the new class and identity confines inside the metropolis.

The same highways that were considered instruments of progress and modernisation in the modernist ideology have become obstructions and barriers in Istanbul, blocking the growth of informal settlements. For Caldeira, the instruments of modernist planning have ironically been used opposite to how they were conceived. The separation between pedestrian and vehicular traffic, which for modernism represented a victory for human health, is seen in Istanbul to be a strategy for prohibiting improper use of the major roadways. The roads are actually sterilised of activities and people who are considered incompatible with the smooth space of flows. Individual private transport has been privileged, excluding the people who use public transport. Similarly, empty urban spaces that in modernist planning were conceived as ‘the right distance between buildings’ or ‘green belts’, have been transformed into areas where sculpture-like, fortified ‘designer’ buildings are located.

The use of highways as a sanitary cordon can also be found in some Asian cities. In the endless suburbs of Jakarta, gated communities, shopping centres and office areas are linked by public or private toll highways. The privileged social classes have moved to the safest and least polluted places in the vast outskirts, abandoning the old unhealthy city, considered to be dangerous, with its poor infrastructures. The major roadways that link the islands of the wealthy bypass the old city centre by soaring over it. In Manila, to build the new toll-road bypass network called the Metro Manila Skyway, various informal neighborhoods were demolished, forcing the inhabitants to evacuate. To reinforce exclusive use of the highway network that connects the residential islands, access is forbidden to traditional vehicles. Jeepneys, buses and motorcycles are thus forced to use the old streets.

The creation of privatised spaces for flows has even invaded the spaces designed for pedestrians. Raised or underground pedestrian routes have emerged in financial centres and for offices, connecting one building to another by bypassing the city streets. Because of this, the streets and squares that for years symbolised public life have slowly and inexorably been replaced by tunnels and skyway bridges. Access to offices by workers and executives is through tunnels and skywalks, without ever having to step out of their cars other than inside a private parking garage. Entrances to buildings are monitored by video cameras and security staff.

The use of tunnels and pedestrian bridges has compromised the indiscriminate life and use of the public streets. In some business centres, simply going somewhere on foot automatically makes one suspect. The street, a place of human activity and chance encounters has been transformed into a realm of fear and surveillance.