The way we design, plan and build our cities and their infrastructure is critical for developing competitive and liveable cities. Cities are already suffering from severe environmental problems, such as pollution, congestion and excessive waste, while the basic needs of hundreds of millions of urban residents are yet to be met. The unprecedented urbanization imposes an even greater challenge for providing adequate housing, energy, water, sanitation and mobility to all. Cities are at a crossroads. Choices made in urban infrastructure development today will determine the success of cities in delivering services to everyone while growing competitively within a protected environment.