Sustainability responses must accelerate to avoid major risks to cities. Climate change impact on cities, likely to be significant if global sustainability initiatives are not quickened, is a paramount example of the ...Sustainability responses must accelerate to avoid major risks to cities. Climate change impact on cities, likely to be significant if global sustainability initiatives are not quickened, is a paramount example of the risk. World wide meetings of city planning practitioners and researchers agree that an urgent agenda is to work together to empower cities and their governments with funds, tools and mentoring to make the responses needed. In the spirit of this urgent agenda, this paper introduces some prac- tical methods for assessing sustainability associated with transport and urban form in our cities. A concept of strategic scans of future scenarios, which underpins the backcasting approach, has been introduced at the 12th World Conference on Transport Research（WCTR） in 2010 and has broken urban and transport planning trend. These strategic scans are based on a sustainability framework, the elements of which provide evidence based drivers of sustainability. The framework culminates in metric visualisations for each of the three pillars of sustainability. The paper details some of the operational aspects of these metrics in the form of environmental sustainability-accessibility space, putting into practice measures of environmental stewardship, social equity, economic efficiency, and the relationship among them. The paper concludes with a call of developing a typology of sustainability performance using the strategic scan methodology to extend the principles of the methodology into a useful tool for city governments and contribute to assembling a database of city forms, transport structures, and their sustainability performances.展开更多
In this paper,the concept of environmental capacity is developed to identify a convenient maximum traffic volume which will not reduce the life quality of residents.The presented method investigates the idea of traffi...In this paper,the concept of environmental capacity is developed to identify a convenient maximum traffic volume which will not reduce the life quality of residents.The presented method investigates the idea of traffic capacity under environmental constraints by calculating the maximum number of vehicles allowed on roads based on acceptable levels of air and noise pollutants.In this study,the permissible noise pollution level and permissible levels of CO and NOxpollution are considered for determining environmental capacity.Results show the significant difference between environmental capacity and functional traffic capacity,introduced by the highway capacity manual(HCM)as a conventional method for estimating functional capacity.Thus,maximum allowed pollution is considered a constraint on a vehicle flow rate,which shows the proper traffic flow for selected streets in Tehran,Iran’s capital.The paper concludes that traffic capacity under noise and air pollution constraints is much less(approximately one-fourth and one-eighth for noise and air pollution respectively)than the current highway capacity estimated using HCM guidelines.Therefore,to save the cities like Tehran from noise and air pollution,traffic flows should be limited to the level of environmental capacity by implementing some travel demand management(TDM)policies like road pricing.展开更多
文摘Sustainability responses must accelerate to avoid major risks to cities. Climate change impact on cities, likely to be significant if global sustainability initiatives are not quickened, is a paramount example of the risk. World wide meetings of city planning practitioners and researchers agree that an urgent agenda is to work together to empower cities and their governments with funds, tools and mentoring to make the responses needed. In the spirit of this urgent agenda, this paper introduces some prac- tical methods for assessing sustainability associated with transport and urban form in our cities. A concept of strategic scans of future scenarios, which underpins the backcasting approach, has been introduced at the 12th World Conference on Transport Research（WCTR） in 2010 and has broken urban and transport planning trend. These strategic scans are based on a sustainability framework, the elements of which provide evidence based drivers of sustainability. The framework culminates in metric visualisations for each of the three pillars of sustainability. The paper details some of the operational aspects of these metrics in the form of environmental sustainability-accessibility space, putting into practice measures of environmental stewardship, social equity, economic efficiency, and the relationship among them. The paper concludes with a call of developing a typology of sustainability performance using the strategic scan methodology to extend the principles of the methodology into a useful tool for city governments and contribute to assembling a database of city forms, transport structures, and their sustainability performances.
文摘In this paper,the concept of environmental capacity is developed to identify a convenient maximum traffic volume which will not reduce the life quality of residents.The presented method investigates the idea of traffic capacity under environmental constraints by calculating the maximum number of vehicles allowed on roads based on acceptable levels of air and noise pollutants.In this study,the permissible noise pollution level and permissible levels of CO and NOxpollution are considered for determining environmental capacity.Results show the significant difference between environmental capacity and functional traffic capacity,introduced by the highway capacity manual(HCM)as a conventional method for estimating functional capacity.Thus,maximum allowed pollution is considered a constraint on a vehicle flow rate,which shows the proper traffic flow for selected streets in Tehran,Iran’s capital.The paper concludes that traffic capacity under noise and air pollution constraints is much less(approximately one-fourth and one-eighth for noise and air pollution respectively)than the current highway capacity estimated using HCM guidelines.Therefore,to save the cities like Tehran from noise and air pollution,traffic flows should be limited to the level of environmental capacity by implementing some travel demand management(TDM)policies like road pricing.
