Although more dispersed urban development is inevitable in some rapidly growing regions of the world, the benefits of such development are unclear, and can represent economic transfers that reinforce existing social inequalities.However, work by the New Climate Economy shows that alternative development paths do exist, such as the ‘3C model’; compact, connected and coordinated urban development that can bring a wide range of economic and social benefits. Prepared as a summary of the work by the NCE and their partners, this working paper adds the very latest global evidence, and provides an overview of international collaborative transport initiatives to promote the use of the 3C model of urban development. The working paper begins by discussing in-depth the current, key trends of urban development and transport use, such as declining urban densities, a reduction in non-motorised transport and public transport, and the significant growth of private vehicle use. The large social, economic, and environmental costs of maintaining these trends are examined, before both costs and benefits are compared to those of the 3C model of urban development. Benefits of the latter include strengthening of local economies, more universal access to infrastructure, cost saving in transport, health benefits, carbon emissions reduction, and increased social equity. The work of the NCE highlights case studies that show that we are already seeing tipping points toward such alternative urban development as the 3C model, yet although technical advances and innovation are currently available, countries and cities face significant barriers to action such as weak fiscal bases for investment, fossil fuel subsidies, vested interests and consumer preferences towards private vehicle travel. The authors explain that international cooperation can amplify and accelerate transformed urban mobility systems, by developing common platforms for action, knowledge-sharing, and capacity-building, as well as by enhancing cities’ access to finance for sustainable transport. Finally, the working paper contains a summary for policymakers, which advises that:

Sustainable transport systems are crucial for underpinning the economic prosperity and performance of nations, as well as for tackling climate change, improving road safety, and reducing air pollution.
In many regions, the business-as-usual pattern of urbanisation and transport mobility remains characterised by unplanned urban sprawl, while intra- and inter-city transport networks are still dominated by conventional motorisation. Unchecked, this trend could lead to a doubling of motor transport by 2030, and a tripling of urban land use.
These trends have already created a myriad of economic, social, and environmental costs which can significantly constrain improvements in quality of life.

For instance, Beijing’s dependence on motorised transport, including congestion and air pollution, is estimated at 7.5–15.0% of GDP, while in the U.S, NCE estimate that urban sprawl costs over $1trillion per annum ($400b in costs to the public purse, and $600b in costs related to private vehicle use).