Analysing proximity to public transport: the role of street network design

The proximity of homes and employment to public transport networks is a key factor in explaining ridership. One of the most frequent strategies for increasing proximity to public transport is to densify the immediate station environment. However, proximity can also be created through the design of the street network in new urban developments. This article analyses the impact of urban design on public transport network coverage and its potential demand by comparing the real situation of the Madrid Metro network with four hypothetical scenarios representing different types of street network: irregular with high density, irregular with low density, orthogonal and station-oriented. By keeping the distribution of population and employment constant, the differences between the real scenario and each of the hypothetical ones can be explained entirely by the role played by the design of the urban fabric. A series of indicators have been calculated to measure the extent of the impact of street network design on the proximity to public transport: surface of the coverage areas, population and employment covered according to proximity bands, access quality and potential demand. The results obtained show that the station-oriented street system would lead to a substantial increase in population and employment in the first coverage bands, thereby generating a highly significant increase in the potential demand for public transport.