The passing of Singapore’s Lee Kuan Yew recently triggered a nationwide outpouring of grief and tributes from leaders from across the world. As the country’s founding father and first Prime Minister, Lee is widely seen as the architect of Singapore’s transformation since the 1950s – from a small, poor trading port with limited natural resources, to a modern metropolis with one of the world’s highest per capita GDPs. In those early years, two thirds of the population lived in inner city slums, with streets strewn with litter and the stink of rotting garbage unavoidable.

Lee, described by U.S. President Barack Obama as a “true giant of history”, helped lift the country out of squalor thanks, in no small part, to his range of housing, healthcare and education policies that put his people first.

Almost four billion people currently live in the world’s cities. That number is expected to jump by 2.5 billion by 2050, with 90 percent of the growth occurring in Asia and Africa. The UN-Habitat says that cities in the developing world, many of which are doubling in size every 15 to 20 years, currently lack the resources to adapt to the forces of urbanization.

Today’s cities will need to accommodate spiralling numbers of people, servicing their needs and stimulating trade and investment to create jobs, all within the constraints imposed by mega-challenges, such as climate change.

Investment, development and technology will be crucially important. The likes of Philadelphia and Singapore are already investing heavily in green stormwater infrastructure to reduce the risk of coastal flooding, for example. New York and Washington D.C. are creating their own mandates to drive out energy waste from buildings. Others are looking at how to use data analytics to develop more sophisticated energy infrastructure.

But the use of smarter technologies and ICT is only part of the solution. Factoring a range of human dimensions into a city’s future vision is going to be crucial too.

We have already witnessed, in places like Masdar (billed as a blueprint for future sustainable cities), what happens when development races ahead of the needs of people. Yes, the global financial crisis of 2008 has inhibited Masdar’s ambitions. But it is the lack of affordable housing that is forcing many of the city’s workers to commute by car to a city aiming to be carbon neutral. Despite projections of some 40,000 people calling it home by 2015, only several hundred students have so far moved in.

Similarly, in the north Thailand city of Chiang Mai, its rapid transformation as a commercial center is altering the socio-economic fabric of the city. Once-dominant small-scale agricultural land is being absorbed by urban sprawl, with small markets replaced by shopping malls. Daily Buddhist rituals are being eroded by the pressure of commuting and a faster pace of life.

Of course, change is at the heart of metropolitan life. But, as English Heritage chief executive Simon Thurley says, maintaining that link with the past creates a feeling of belonging among residents. “Buildings erected 100 years ago are integral to the look, feel and character of a place. Take them away and a city loses part of its identity,” he says. He wants cities to embrace the challenges of reusing defunct infrastructure in the same way New York’s Meatpacking District’s old industrial buildings are now home to high-end boutiques, bars and restaurants.

What about the design and layout of a city? For Jeff Risom, the U.S. managing director at Gehl Studio, “our streets could be doing more than just allowing people and objects to move from A to B.” Melbourne and Copenhagen, placed first and second respectively in the latest Economist Intelligence Unit’s Global Liveability Ranking, both spend time assessing the vitality of public life based on people-centered metrics such as pedestrian flow and time spent lingering in an area. The Danish capital has promised to increase pedestrian traffic and the time spent in public spaces by 20 percent compared with 2010 figures by the end of the year – and to raise the share of citizens satisfied with the city’s public spaces to 80 percent.

There are a myriad of examples where people are at the heart of city policy-making and progress is being made by city managers and mayors. Today, cities and companies are more agile and progressive than countries. As a result, cities are the frontrunners of fostering sustainable solutions in their effort to become more liveable, sociable and long-term beneficial to their inhabitants. And making our cities optimal for tomorrow’s citizens is at the heart of AkzoNobel’s Human Cities initiative, designed to help find ways of making our urban environments more inspiring, energizing and vibrant.

We want city leaders to focus on issues such as heritage, color, transport, education and sport to create places that serve people better. From the creation of age-friendly cities, like Madrid (which has developed city-planning strategies to ensure design works for people of all ages and levels of ability), to a focus on green space provision as a tool for improving the lives of poor families (as is the case in cities across Chile where evidence suggests that parks not only benefit the environment and cut crime rate, but also give citizens a sense of pride and belonging), these case studies offer inspiration and hope that cities of the future will be places in which we will want to live and play, rather than just exist.

We just might need a few more Lee Kuan Yews to make it happen.

Many of the issues raised here are explored in more details in the Economist Intelligence Unit’s report, ‘Tomorrow’s Cities’ which you can find here.