Access to people, goods, services, and information is the basis of economic development in cities. The better and more efficient this access, the greater the economic benefits through economies of scale, agglomeration effects, and networking advantages. Cities with higher levels of agglomeration tend to have higher GDP per capita and higher levels of productivity. The way in which cities facilitate accessibility through their urban forms and transport systems also impacts directly on other measures of human development and well-being. Urban travel currently constitutes more than 60% of all kilometres travelled globally (van Audenhove, Korniychuk et al. 2014) and, as a result, urban transport is currently the largest single source of global transport-related carbon emissions and the largest local source of urban air pollution.
This paper will present evidence first on how accessibility in cities is created through the co-dependence of urban form and transport systems and how this relates to urban carbon emissions. This paper is primarily based on an extensive literature review and aims to assist a further reframing of the urban transport debate by emphasizing accessibility as the underlying objective of mobility and transport in cities. Above all, such a reframing implies a far greater recognition of urban form characteristics such as land use, the distribution of densities, and urban design, in addition to more conventional transport characteristics such as related infrastructure, service levels, and travel speeds.