Cities drive growth because of their ability to bring together firms and workers in a way that allows for large scale and specialised production. With a large pool of connected individuals, people can specialise in particular tasks and be matched to jobs that are most suited to them, and firms can specialise to meet the specific demands of consumers.
Urban mobility is at the heart of this process, fundamentally determining a city’s potential for productivity and liveability. Unless people and products can move efficiently across the city, firms get locked into small-scale unproductive activities, and people cannot access basic goods and services. This is the case in many developing cities, where non-existent walkways, crippling traffic jams and weak public transport systems undermine the city’s connectivity.
Policymakers in these contexts face difficult trade-offs in improving systems of mobility, both in addressing growing demands for private transport, and in investing in public transport links in a city. Learning from the experiences of cities across the globe facing these challenges offers some key lessons for enhancing mobility in cities; by complementing investments in infrastructure with smart regulation, cities such as Singapore and Lagos have been able to meet growing demands for transport. Not only do these investments help to overcome the potential downsides of density – they can kick off a development process by credibly signalling to investors of where future economic activity will cluster.
- Building roads is not enough. Though investment in road infrastructure is vital in expanding access in a city, this comes at a high cost and is unlikely to solve the problem of congestion in developing cities. Evidence from US cities suggests that as incomes and populations rise, vehicle use will rise to fill new roads. Infrastructure needs to be met with regulations on private cars and investment in public transit.
- Existing informal transport is a complement, not a substitute, for higher capacity systems. In many developing cities, informal minibuses and motorbikes form the backbone of public transport. Even as governments invest in higher capacity transport modes, these systems will continue to provide essential feeder services from low density areas. Regulation can improve the quality of these services but this can come at the cost of affordability or quantity.
- In many cases, bus rapid transit systems can alleviate congestion problems at a fraction of the cost of rail based systems. Rail based systems have significant advantages in terms of their relative limited land use and environmental sustainability – but it is only at very high levels of urban density that investing in light rail or mass rapid metro rail may make sense in terms of overall cost effectiveness.
- Link transport investments with land use in a city. Urban density is a crucial determinant both of the desirability and financial sustainability of higher capacity transport systems. Linking transport systems with land use and land use planning can massively enhance the benefits of investing in connectivity.
An extended Cities that Work synthesis paper on urban mobility is available here.