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Wang Z.,China Sustainable Transportation Center | Li Y.,Kunming Urban Planning and Design Institute
Mitigation and Adaptation Strategies for Global Change | Year: 2015

Super block and giant road networks have been a dominant form of China’s new town development. This may lead to numerous urban problems, such as high automobile dependency, heavy traffic congestion, and unwalkable communities. In recent years, the transformation of superblocks to a new urban form with human-scale blocks and fine-grain grid road networks in certain cities in China has drawn much attention. Despite its recent positive attention, the following important questions have been raised: How will the transformation impact road network capacity? How will the changes contribute to transportation carbon emission (CE) reduction or increase? How will cities deal with rearranging the cost structure among the different stakeholders in road construction, maintenance, and management? Related factors and approaches for a solution to such issues are discussed in this study, followed by further analysis using a case study of the core area of Chenggong, a new town in Kunming, China. The study shows that concern about a negative impact on road network capacity is unfounded. Estimation using empirical data from other cities shows that a significant CE reduction is likely to be achieved; and through reasonable cost restructuring and management, a win-win situation is possible for all road construction, maintenance, and management stakeholders. Thus, an optimized societal cost-benefit arrangement can be reached through the transformation. © 2014, Springer Science+Business Media Dordrecht.


Wang Z.,China Sustainable Transportation Center | Koutsopoulos H.N.,KTH Royal Institute of Technology
Proceedings - Winter Simulation Conference | Year: 2011

Rail simulation model calibration is a process of adjusting model parameters while comparing model output with observations from the real rail system. There is a lack of systematic methodology for calibrating urban rail simulation models. Based on a simulator developed for urban rail operations and control, the paper demonstrates a methodology of calibrating model parameters, and specifically, fine-tuning some of the simulation inputs. The calibration process is modeled as a multi-variate optimization problem and solved by the Simultaneous Perturbation Stochastic Approximation (SPSA) algorithm. A case study of the Massachusetts Bay Transportation Authority (MBTA) Red Line shows that the methodology improves the simulation model dramatically in terms of replicating the track block runtimes. At the same time, it upgrades the station specific dwell time parameters and enhances a-priori boarding rates at stations fairly effectively. © 2011 IEEE.


Wang Z.,China Sustainable Transportation Center | Wang J.,China Sustainable Transportation Center | He D.,Energy Foundation
Transportation Research Record | Year: 2012

Promoting transit has been a national strategic policy as part of the effort to relieve traffic congestion in China. However, such promotion also offers a great potential benefit in carbon dioxide (CO2) abatement, to which insufficient attention has been paid. For the effects of transit priority policies on CO2 emissions to be understood, an evaluation and a sensitivity analysis were conducted. The relationship between public transit and CO2 emissions with respect to four contributing factors is discussed. The effectiveness of transit priority policies implemented in recent years was analyzed, and its correlation to CO2 emissions was identified. The magnitude of transit CO2 emissions from 2000 to 2008 was estimated. On the basis of varied assumptions, six scenarios were designed to analyze the sensitivity and the range of possible CO2 abatement potentials of different policies. Finally, some recommendations for future policies from the perspective of reducing CO2 are presented.


Wang J.,China Sustainable Transportation Center | He D.,Energy Foundation
Mitigation and Adaptation Strategies for Global Change | Year: 2015

China is undergoing rapid urbanization, along with economic growth and transport automation. Because it is densely populated, China is constrained by natural resource limitations and potential impacts of global climate change. Significant challenges for sustainable urban development include urban sprawl, traffic congestion, air pollution, city layouts not oriented to twenty-first century lifestyles, declining traditional urban culture, selective over-development, and social inequities. Increasing awareness of these pressing problems has led national and provisional governments and cities to seek sustainable urban development solutions. Central ministries and non-government organizations have implemented pilot projects demonstrating best practices in the Chinese context. These are being scaled up to develop local and national guidelines and policies. This paper describes China’s urbanization issues and national and local efforts toward the realization of sustainable urbanization. It is hoped that China’s urbanization trends and challenges will stimulate sustainable and low-carbon concepts and approaches that can enrich sustainable urbanization theory and practices in and beyond China. © 2015, Springer Science+Business Media Dordrecht.


Jiang Y.,Tsinghua University | Jiang Y.,China Sustainable Transportation Center | Zegras P.C.,Massachusetts Institute of Technology | He D.,The Energy Foundation Beijing Office | Mao Q.,Tsinghua University
Mitigation and Adaptation Strategies for Global Change | Year: 2015

Rapidly increasing transportation energy use in China poses challenges to national energy security and the mitigation of greenhouse gas emissions. Meanwhile, the development of automobile oriented neighborhood structures, such as superblock housing, currently dominates urban expansion, and construction in Chinese cities. This research takes an empirical approach to understanding the relationship between neighborhood type and household travel energy use in Jinan, China, by examining nine neighborhoods that represent the four types of urban community commonly found in Chinese cities: traditional, grid, enclave, and superblock. After conducting a survey, we derive disaggregate household transport energy uses from the’ self-reported weekly travel diaries. Comparative analysis and two-step instrumental variable models are employed. Results show that, all else being equal, households located in superblock neighborhoods consume more transportation energy than those in other neighborhood types, because such households tend to own more cars and travel longer distances. Proximity to transit corridors and greater distance from the city center are also associated with higher household transport energy use in these neighborhoods, although both impacts are minor, partially because of the offsetting effects of car ownership. Overall, the analysis suggests that, to help chart a more energy-efficient future in urban China, policymakers should (1) examine past neighborhood designs to find alternatives to the superblock, (2) focus on strategic infill development, (3) encourage greater use of bicycles and e-bikes as a substitute for larger motorized vehicles, (4) improve the efficiency of public transportation, and (5) consider ways to shape citizens’ preferences for more energy-efficient modes of travel. © 2014, Springer Science+Business Media Dordrecht.


Jiang Y.,China Sustainable Transportation Center | Christopher Zegras P.,Massachusetts Institute of Technology | Mehndiratta S.,The World Bank
Journal of Transport Geography | Year: 2012

This paper examines BRT station walk access patterns in rapidly urbanizing China and the relationship between bus rapid transit (BRT) station context and corridor type and the distance people will walk to access the system (i.e., catchment area). We hypothesize that certain contextual built environment features and station and right-of-way configurations will increase the walk-access catchment area; that is, that urban design influences users' willingness to walk to BRT. We base our analysis on 1233 user surveys, conducted at 19 BRT stations along three existing (as of summer 2009) BRT corridors in the city of Jinan. Ordinary least squares regression is applied to estimate the relationship between walk access distances and aggregate station- and corridor-area characteristics, controlling for individual- and trip-specific attributes. The results suggest that people walk farther to BRT stations when the walking environment has certain features (median transit-way station location, shaded corridors, busy and interesting). Trip and trip maker characteristics play a relatively minor role in defining BRT walk access distance. Implications include the need for flexible transit station catchment area definitions in identifying transit-oriented development opportunities and estimating system demand. © 2011 Elsevier Ltd.


Li X.,University of Wisconsin - Milwaukee | Liu Y.,University of Wisconsin - Milwaukee | Liu D.,China Sustainable Transportation Center | Gao Z.,Chongqing Urban Transport Planning and Research Institute
Journal of Urban Planning and Development | Year: 2016

This paper presents a multidimensional framework to evaluate, monitor, and compare the development of public transportation systems towards Transit Metropolis status in different cities in China. In the proposed framework, a policy level is designed to better capture a city's characteristics and developing priorities as well as the subjective opinions of various transit stakeholders, based on which technical criteria are further compared and assessed in the technical level with an enhanced fuzzy analytical hierarchy process (AHP) model, where a nonlinear optimization formulation is proposed to maximize the consistency in pairwise comparison and weight estimation. The proposed framework offers the advantage of preventing the vagueness and uncertainty of decision-maker(s) when evaluating technical criteria while properly retaining the policy preferences from decision-makers. A case study of nine cities in the Chongqing metropolitan area, China, reveal that the proposed model can effectively evaluate the performance of public transportation system development at different levels of detail. It can be used to generate the rankings of different cities and also to identify deficiencies and areas of improvement. © 2015 American Society of Civil Engineers.


Chen S.P.,China Sustainable Transportation Center | Liu D.Z.,China Sustainable Transportation Center
Advanced Materials Research | Year: 2013

This research explores the application of available information from Automated Data Collection Systems (ADC) with a focus on bus passenger Origin-Destination (OD) matrices inference, using Chongqing as a case study. It demonstrates the feasibility and ease of applying to infer bus passengers' boarding and alighting locations if boarding information is available from neither Automatic Fare Collection System (AFC) nor GPS data, and is the first known attempt to create an algorism to use stop Geographic Information System (GIS) and dual-direction bus stop group to estimate the boarding location and traveling direction when GPS data cannot provide the arriving information at bus stops. The results of this research have been practically applied to a full-size bus network in Chongqing, and can be easily implemented to other Chinese cities as Chongqing presents most popular data structure of ADC in China. © (2013) Trans Tech Publications, Switzerland.


Liu D.,China Sustainable Transportation Center | Chen S.,China Sustainable Transportation Center
IET Conference Publications | Year: 2011

Many large Chinese cities are constructing metro systems in order to solve the problems in traffic. A productive and effective way to optimize and integrate the bus network with metro systems is required to form a unified city transit network. This study introduces a method to evaluate the transit network bus route optimization based on key performance indicators, which takes into consideration three interest groups: transit operators, passengers and transit management agency. This study has been applied in Chongqing transit bus network optimization and integration along the metro corridors. The results show that this method well balances network efficiency and the benefits of companies and of passengers.


Chen S.,China Sustainable Transportation Center | Liu D.,China Sustainable Transportation Center
IET Conference Publications | Year: 2011

In many Chinese cities, because of the lack of transit priority mechanism and real-time control measures, transit headway regularity at bus stops is usually disturbed. Transit headway irregularity not only leads to longer waiting time but also affects passenger distribution in vehicles. How to reflect the influence of headway irregularity on passenger distribution of neighboring vehicles is the key issue addressed in this article. Firstly, the relationship between one vehicle's headway at different stops was analyzed. Based on this, a model of vehicle passenger volume was established. Finally, a passenger variability rate model of neighboring buses is proposed to measure the uneven passenger distribution of neighboring vehicles. The model is calibrated through the case study of boarding and alighting survey on three bus routes, actual headway observation and time delay survey. The survey data analysis indicates that headway variability rate of neighboring vehicles is positively correlated with the passenger variability rate of two neighboring buses.

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