UN-Habitat, the United Nations Programme for Human Settlements on Tuesday launched a new report exploring the link between street connectivity and city prosperity which includes the Composite Street Connectivity Index.
The report, launched by the agency’s Executive Director Dr. Joan Clos, finds that cities with good street connectivity have been able to achieve higher overall rates of city prosperity – incorporating infrastructure, environmental sustainability, productivity, quality of life and equity and social inclusion – because strong street layouts facilitate the effective provision of services and efficient mobility of people and goods.
Speaking at the launch, Dr Clos said: “We know that well-planned cities have around 30 to 35 per cent of land allocated to the streets. [With the Composite Street Connectivity Index] now we can begin to look at the variables within this allocation – such as the number of street intersections per square kilometer – and this is very important.”
The lead author of the report, UN-Habitat’s Gora Mboup, also spoke at the launch highlighting that the new index provided the missing link between street land allocation and the City Prosperity Index and would provide a strong evidence base for urban policy.
“A good street pattern boosts infrastructure development, enhances environmental sustainability, supports higher productivity, enriches quality of life, and promotes equity and social inclusion,” says Dr Clos in the book’s foreword. “In the history of cities… streets, plazas and designed public spaces have contributed to define the cultural, social, economic and political functions of cities.”
UN-Habitat advocates for at least 30 per cent allocation of land to streets in city planning. Cities in developing countries such as Kenya’s capital Nairobi has only 10 per cent land allocated to streets, putting it in the group of cities with low levels of land allocated to streets (below 15 per cent). Some areas, including the densest, Kibera, and one of the least dense, Muthaiga, have as little as 3 per cent. This suggests that city planners did not plan for a city with many streets or intersections, a mistake that has resulted in heavy traffic jams not just in the city’s core area, but also in the suburbs.