首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到9条相似文献,搜索用时 0 毫秒
1.
Mitigation of greenhouse gas emissions from transportation has become increasingly important and challenging especially for developing countries. This paper takes the inter-city passenger transport in China as a case, and develops a system dynamics model for policy assessment and CO2 mitigation potential analysis. It is found that the future demand for China’s inter-city passenger transport is expected to be large, with the turnover volume growing at a rate of 9% per annum and amounting to 6600 billion p-km in 2020. Major emissions reduction potential exists in inter-city passenger transport. In 2020, comparing to the case without any specific policies stressing mitigation, the reduction of CO2 emissions ranges from 26% to 32% under those scenarios with policy controls. Sensitivity analysis reveals that the CO2 mitigation will be best achieved by accelerating the development of railway network, together with slowing down the extension of highway network and imposing fuel taxes.  相似文献   

2.
This paper describes tailpipe emission results generated by the Vehicle Performance and Emissions Monitoring system (VPEMS). VPEMS integrates on‐board emissions and vehicle/driver performance measurements with positioning and communications technologies, to transmit a coherent spatio‐temporally referenced dataset to a central base station in near real time. These results focus on relationships between tailpipe emissions of CO, CO2, NOx and speed and acceleration. Emissions produced by different driving modes are also presented. Results are generally as one would expect, showing variation between vehicle speed, vehicle acceleration and emissions. Data is based upon a test run in central London on urban streets with speeds not exceeding about 65 km/h. The results presented demonstrate the capabilities of the system. Various issues remain with regard to validation of the data and expansion of the system capability to obtain additional vehicle performance data.  相似文献   

3.
Few studies have examined the relationship between micro-scale features of the built environment and street segment usage. Micro-scale features of the built environment include the width of the sidewalk, the presence of amenities such as benches and trash bins, and the presence of crossing aids such as stoplights and crosswalks. This study employs segment-level primary data collected for 338 street segments in close proximity to one of 71 bus rapid transit stations in Bogotá, Colombia. We also use secondary data to control for area-level characteristics such as density, socio-economic stratum, unemployment, and crime. Factor and regression analyses are to use identify two dimensions of the built environment that are associated with higher levels of pedestrian activity: pedestrian-friendly amenities, comprised of wider and higher quality sidewalks and the presence of amenities such as benches, garbage cans, and bike paths; and connectivity, comprised of higher levels of road density, three- and four-way intersections, and density. In addition, we find greater pedestrian activity on segments with higher development intensity, with more mix of land uses, and with more crossing aids. Although the relationships identified are not causal, they are suggestive in terms of planning successful built environment interventions.  相似文献   

4.
We use social-eco-efficient analysis in the form of SEEbalance to evaluate gravel transport sustainability for trucking and two kinds of intermodal transportation. Results show that switching from trucks to intermodal transportation can improve the sustainability of gravel transportation in the northeast corridor of Taiwan. Sensitivity analysis shows that rail combined with truck intermodal transportation has competitive advantage despite the terminal’s location factor.  相似文献   

5.
This paper develops a new method to solve multivariate discrete–continuous problems and applies the model to measure the influence of residential density on households’ vehicle fuel efficiency and usage choices. Traditional discrete–continuous modelling of vehicle holding choice and vehicle usage becomes unwieldy with large numbers of vehicles and vehicle categories. I propose a more flexible method of modelling vehicle holdings in terms of number of vehicles in each category, using a Bayesian multivariate ordinal response system. I also combine the multivariate ordered equations with Tobit equations to jointly estimate vehicle type/usage demand in a reduced form, offering a simpler alternative to the traditional discrete/continuous analysis. Using the 2001 National Household Travel Survey data, I find that increasing residential density reduces households’ truck holdings and utilization in a statistically significant but economically insignificant way. The results are broadly consistent with those from a model derived from random utility maximization. The method developed above can be applied to other discrete–continuous problems.  相似文献   

6.
The interrelatedness of transportation development and economic growth has been a constant theme of geographic inquiries, particularly in economic and transportation geography. This paper analyzes the expansion of China’s railway network, the evolution of its spatial accessibility, and the impacts on economic growth and urban systems over a time span of about one century (1906–2000). First, major historical events and policies and their effects on railway development in China are reviewed and grouped into four major eras: preliminary construction, network skeleton, corridor building, and deep intensification. All four eras followed a path of “inland expansion.” Second, spatial distribution of accessibility and its evolution are analyzed. The spatial structure of China’s railway network is characterized by “concentric rings” with its major axis in North China and the most accessible city gradually migrating from Tianjin to Zhengzhou. Finally, the study indicates that railway network expansion has significantly improved economic development and heavily influenced the formation of urban systems in China.  相似文献   

7.
This paper presents an approach to include both the unstorable feature of transportation service and the technological differences within railway companies in efficiency and effectiveness measurements. We explore efficiency and effectiveness for a group of 40 global railways in the year 2002, using traditional data development analysis (TDEA) and network data development analysis (NDEA). Comparing the results obtained from the NDEA model with those from the TDEA indicate that performance measures are quite different in terms of the magnitude, and even using different DEA type models to evaluate railway system performance does not distort the ranking of their performance. We also analyze the inter-related effects among three performance measures, finding that transportation service characteristics have positive effects on the evaluation of performance. Generally speaking, the NDEA model provides deeper insight regarding the sources of inefficiency and process-specific guidance to railway managers so as to help them improve their railway’s performance.  相似文献   

8.
This study proposes a methodological framework to incorporate latent factors, including direct and indirect perceptions, as the explanatory variables in a discrete choice models using revealed preference and stated preference data sets. The methodology requires the estimation of a model system comprising of a discrete choice model and the structural and measurement equations of a latent variable model. The application involves the evaluation of responses to the new high occupancy vehicle (HOV) lanes on the Sun Yat‐Sen Freeway in Taiwan. The results obtained from this study provide valuable insights into the planning and assessment of HOV lanes.  相似文献   

9.
We compare the passenger transportation systems of Buenos Aires, Chicago and São Paulo. The selected cities represent distinctive combinations of land-use, infrastructure, and evolution of transport policy. Analysis is centered on accessibility to downtown areas, where transportation processes converge in an environment where space is scarce. In two of the three cities institutional arrays that legally establish unified decision making have shown little capacity to launch fare or physical coordination between modes. In two of the three cities the concentration of public transportation supply to historical downtowns has not been an attraction factor, and downtown uses have expanded to less accessible areas. Gentrification in Chicago is also another process showing that land use changes are related to many factors, transportation being only one of them, and not always a necessary one. In all three cases the use of railways, as a set of inherited infrastructures, has seen an increase whose magnitude suggests a link to modal reassignment due to increasing congestion. Scarcity of space in old downtown areas is being counteracted through more intense use, or through the expansion of vertical space for transportation operations.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号