Towards The Sustainable City: The Impact Of Transport-Land Use Interactions, Deliverable 6. The Final Report

Very few transport studies have been able to demonstrate that transport policy measures alone can improve sustainability by reducing fuel consumption and emissions below existing levels. There is therefore an increasing interest in the use of coordinated transport-land use policies, but a lack of understanding of relevant relationships. This research sought to obtain greater insight into these relationships. The main objectives were: (i) to increase our understanding of the impact of accessibility and environmental quality on individuals’ and firms’ location decisions; (ii) to use the findings of (i) to enhance a newly developed strategic transport and land use interaction model; (iii) to use the enhanced model to assess the implications for urban sustainability of the impact of transport policy on location choice; and (iv) to use the enhanced model to assess the relative performance of different combinations of transport and land use strategy. \ud \ud There were two main strands to the work. The first involved the use of a newly developed strategic transport-land use model DELTA/START to test the effects of a range of values for environmental and accessibility coefficients. The tests were based on Edinburgh, and included several combinations of road pricing, fares reductions and light rail, and an alternative land use strategy. The second strand involved a literature review and survey work undertaken in Edinburgh using a stated preference approach to identify values for environmental indicators and accessibility to feed into the model. \ud The survey work of households and businesses was successful in producing values for environmental quality and accessibility. We found that changes in air quality were valued more highly than corresponding changes in noise levels. The survey also revealed some interesting issues that merit further investigation: deteriorations in environmental quality were valued more highly than improvements, there was a greater resistance to increases in council tax beyond current levels than up to current levels and valuations were higher where conditions were worse. \ud \ud The transport strategies were predicted to induce considerable shifts in activity, with city centre populations increasing by up to 20%. However, these substantial changes in activity had relatively small impacts on the transport indicators. The results for the alternative land use scenario showed similar effects. Generally it appears, from the tests involving the strategic transport model that the effects on transport indicators of land use changes, whether induced through transport strategies or imposed through land use planning, are an order of magnitude lower than those of the transport strategies themselves. This is an important policy result since it calls into question how much can be achieved by pursuing coordinated land use and transport strategies. \ud