The pace of urbanization at times threatens to overwhelm the city. Traffic congestion, lack of services, loss of amenities and open space, water shortages, and air pollution are all too familiar "costs" of rapid urbanization to Istanbulis. In the 1980s, during the administration of Mayor Bedrettin Dalan, a major urban renewal effort was initiated that included new roads and bridges to ease traffic congestion, removal of dilapidated warehouses and noxious factories, creation of waterfront parks, a natural gas distribution network, and improvements in water supply and sewage collector systems (Panel 24) .These efforts at urban renovation have not always gone unchallenged. The "greening" of the Golden Horn and the construction of inner-city freeways involved the destruction of residential neighborhoods. The pace of unrestrained construction and attempts to create a modern city sometimes threaten more modest programs intended to conserve and re- store the city's architectural heritage. Moreover, despite efforts to improve the flow of traffic and upgrade urban transportation systems, the city remains congested; each day thousands of Istanbulis crowd the ferries and buses commuting between neighborhood and work over ever-greater distances. Conversion to natural gas has been slow and many residents of the city continue to use poor quality coal and lignite for domestic fuel, creating serious air pollution incidents particularly in winter.

Many of those who have moved to the city in recent years live In settlements called gecekondus, literally "placed there by night," reflecting the speed with which houses were illegally erected on vacant land. By some estimates over 50% of the city's population was living in such areas in the 1980s. Although authorities frequently demolished illegal structures, such was the speed with which the buildings appeared or were rebuilt, and so desperate was the need for housing, that it was not unusual, particularly during election campaigns, for entire neighborhoods to receive construction pardons. Over time, therefore, many of these squatter settlements have acquired legal status and are now functionally and administratively integrated into the urban fabric. Make-shift houses have been replaced by more permanent residences and modest apartment blocks (Panel 25) .Where city ser- vices remain inadequate, residents frequently organize themselves or receive assistance from non-governmental or religious organizations to improve water supply, pave streets, establish a clinic, or start a bus service. Illegal construction has not been confined to the gecekondus; many of the new villas along the Bosphorus lack necessary permits or fail to conform to city building regulations.

Although threatened by the pace of construction, by pollution and congestion, and by sometimes ill-conceived programs of urban renewal, Istanbul remains a vibrant city where the legacy of sixteen centuries is still visible in the urban fabric and in the lives of its population. Moreover, the new migrants bring their own energy and vitality to the city. Istanbul may no longer be the capital of a great empire, but it continues, by virtue of its cultural heritage, its economic activity, its geographic setting, and the vibrancy of its population, to be a great world city.