Analysing Sustainable Urban Transport and Land-Use : Modelling tools and appraisal frameworks

Abstract: Sustainable development and climate change is high on the agenda for most cities around the world today. Urban transport is at the heart of these changes. Increasingly, it is recognised that not only is the emission of pollutants and greenhouse gases a problem, but also the detrimental effects of congestion and social exclusion. In order to address these issues, it will be necessary for cities to make strategic long term decisions regarding the future infrastructure and land use, not only in terms of what will be built, but also on measures that affect how these systems are used.This thesis is focused on the decision support tools that we need in order to make well informed decisions. Models that predict the performance of future scenarios, and appraisal frameworks that help evaluate whether these outcomes are desirable or not. The first two papers experiment with different ways of bringing some aspects of sustainability into the appraisal frameworks used to analyse long term strategies. Paper I addresses intergenerational fairness, and Paper II focuses on the emission of greenhouse gases. Paper III develops a model, Scapes, that can help us to better understand the daily travel behaviour, through an activity based approach. By explicitly modelling space-time constraints, and travel time uncertainty in a microeconomic framework, we can get a better understanding of how people can respond to, and value, changes in the transport system. Papers IV and V describe a new integrated land use and transport model, LandScapes.The policy implications from the studies in Papers I, II, and V are that it will be very difficult for Stockholm to reduce its emissions of CO2. Particularly, predicted economic and population growth will inevitably lead to more transport. It is likely that a range of different policies will be necessary to solve that problem. At the same time, we must not forget that decreasing CO2 emissions, although important, is not the only objective Stockholm has. To cope with the increasing travel demand from a growing population, it may well be necessary to build new infrastructure as well. This thesis does not prescribe any such relative valuation between conflicting objectives. It only helps bring them to the fore.