Stars, Diamonds, Petals and Rings: the Varied Shapes of Rail Station Pedestrian Catchment in South England and Their Implications
Ying Jin, University Of Cambridge, Steve Denman, University Of Cambridge
We report a detailed study of pedestrian catchment areas around rail hubs in South England that face strong growth prospects. Their configurations are surprisingly varied, with significant implications on efficiency and sustainability. The study provides new insights into future planning, investment and governance.
Although its precise role is still a matter of considerable debate, the pedestrian catchment of a rail station (variously defined as within half mile to one mile radius) features prominently in both urban land use and transport planning literature. They are usually delineated by circles of a certain radius from the station indicating e.g. the high priority areas of transit-oriented development or main beneficiaries of the rail services, with little regard of whether the street layout and land use regulations facilitate the expected level of catchment access in practice.
This seemingly minor simplification has obscured major differences in the actual and potential advantages of different street layouts and land use regulations within such catchments. Because the street layouts and land use regulations are difficult to change without a commonly shared understanding of their significance, the long standing neglect of their roles in facilitating efficient and sustainable development has hampered the efficacy of successive generations of land use development and local traffic planning proposals.
We choose a range of important urban, suburban and exurban rail hubs in Southern England that face similarly strong growth prospects as our case studies. The motivation for doing so is to make a relatively direct contribution to on-going planning and transport studies and decision-making. We pull together a number of hitherto unconnected mapping and network datasets to give a detailed and precise representation of the catchment areas. We have then carried out a detailed analysis of the effects of different street layout and land use regulations on the extent of pedestrian catchments by walking time isochrone. Surprisingly, the catchments vary greatly both in shape and the overall land coverage: those with the smallest coverage show a star shape, followed by those of diamonds and petals. All of the actual catchments are but a fraction in coverage, suggesting that the practice of representing pedestrain catchments in rings of circles is in most instances grossly misleading and should be modified. We have in the process developed a tool that can be used to produce easily the realistic ctachment isocrones.
England has the longest history of railway use. Our findings suggest that improvements in street configurations around rail stations are rarely a function of time. Rather, concerted interventions are required through land use planning, zoning regulations, urban design, building design, traffic planning, landscaping and governance. Such interventions are very difficult to implement because of high costs and conflicts in local interests. However, history shows that major growth in rail travel provides the rare impetus for such changes. We discuss how the insights gleaned from the evolution of the rail station catchments can be used to guide the development process, and project for a sample of stations the alternative growth trajectories. We conclude by assessing the alternative trajectories.
Association for European Transport