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The growth curves of fractal dimension of urban form take on squashing effect and can be described by sigmoid functions. The fractal dimension growth of urban form in western countries can be modeled by Boltzmann's equation and logistic function. However, these models cannot be well applied to the fractal dimension growth curve of Beijing city, the national capital of China. In this paper, the experimental method is employed to find parametric models for the growth curves of fractal dimension of Chinese urban form. By statistical analysis, numerical analysis, and comparative analysis, we find that the quadratic Boltzmann equation and quadratic logistic function can be used to characterize how the fractal dimension of the urban land-use pattern of Beijing increases in the course of time. The models are also suitable for many cities in the north of China. In order to convert the empirical models into theoretical models, we attempt to construct a model of spatial replacement dynamics of urban evolution, from which the logistic model of urban fractal dimension growth can be derived. The models can be utilized to predict the rate and upper limitation of Chinese urban growth. In particular, the models can be employed to reveal the similarities and differences between the fractal growth of Chinese cities and that of the cities in western countries. • The squashing effect of limit values of fractal dimension leads to sigmoid curves. • Urban fractal dimension growth curves can be modeled by quadratic Boltzmann equation. • Quadratic Boltzmann equation can be reduced to a quadratic logistic function. • Fractal dimension growth curves of urban form fall into two types. • Fractal dimension growth curves indicate two types of spatial dynamics of cities. [ABSTRACT FROM AUTHOR]

In this paper, we present a formal analysis of the neighborhood vibrancy created by urban form. We use Geographic Information Systems (GIS) to develop quantitative measures of urban form and define neighborhood vibrancy based on a GPS-based activity survey in suburban Beijing. An Urban Form index was adopted to determine that our measures of urban form capture meaningful differences in the characteristics of urban neighborhoods – differences that may have direct impacts on neighborhood vibrancy. Specifically, high density and mixed land use are strongly positively correlated with neighborhood vibrancy, whereas developed external traffic systems are negative. However, a thorough inter-circulation system and convenient accessibility do not always boost neighborhood vibrancy. These factors lose efficacy when gated neighborhoods are selected and surrounding facilities are distributed far away. Our study argues that urban planners, using their professional judgment, can contribute to urban vitality at the neighborhood scale. [ABSTRACT FROM AUTHOR]

• Metro expansions exert spatial distribution effects on subway-side and road-side access. • Subway access improvements generate significant effects on transit use. • Residential self-selection plays a role in moderating the effects. This paper explores the impact of subway development on commuting behavior that arises from changes in network access induced by travel time reductions under geographical contexts of China's mega-city subway network expansion. The analysis is carried out on a cohort of residential areas in Beijing built from geographically-referenced data on individual surveys, administrative records and changes in subway network. We find that improved subway access increase subway use, mainly due to road-side distance reductions to subway stations rather than subway-side distance contractions. Automobile use is significantly reduced due to subway-side access changes along with the subway network expansion. The effects are robust to the consideration of travel attitudes, residential self-selection and other social and spatial gradients. Our results highlight an important implication that access is dynamic in nature and its decomposed subway-side and road-side access can be a key force for guiding metro-system development and station location placements. [ABSTRACT FROM AUTHOR]

Abstract: Tour or trip chain based travel analysis has been a feature of transportation research for several decades, but has largely been the preserve of developed countries. Furthermore, the important associations between urban form and trip-chaining behaviour have received little attention. Based on detailed land use data and an activity dairy survey for workers in Beijing, China, this paper investigates how socio-demographic attributes of households, individuals and urban form characteristics at both residence and workplace, correlate with the tour-based travel decision process. We focus on tour frequency, tour scheduling (type and order of stops made) and tour interdependence mechanisms. Empirical results show that socio-demographic attributes and commuting time strongly correlate with tour decisions, but that there is no significant gender difference in tour frequency, as seen in developed countries, although women tend to make more stops within a tour. Urban form characteristics at home and at workplace are significantly associated with tour frequency, but differ with respect to tour complexity. For example, higher residential density is associated with more home-based tours with fewer stops, while mixed land use at workplaces having higher density and accessibility is associated with more stops within one work tour, or a more complex tour pattern. The research also reveals, for the first time, a tour interdependence effect for workers who undertake multiple tours. [Copyright &y& Elsevier]

Urban form takes on properties similar to random growing fractals and can be described in terms of fractal geometry. However, a model of simple fractals is not effectual enough to characterize both the global and local features of urban patterns. In this paper multifractal measurements are employed to model urban form and analyze urban growth. The capacity dimension D0, information dimension D1, and correlation dimension D2 of a city's pattern can be estimated utilizing the box-counting method. If D0 < D1 < D2 significantly, the city can be treated as a system of multifractals, and two sets of fractal parameters, including global and local parameters, can be used to spatially analyze urban growth. In this case study, multifractal geometry was applied to Beijing city, China. The results based on the remote-sensing images taken in 1988, 1992, 1999, 2006, and 2009 show that the urban landscape of Beijing bears multiscaling fractal attributes. The dimension spectrum curves show several abnormal aspects, especially the upper limit of the global dimension breaks through the Euclidean dimension of embedding space and the local dimension fails to converge in a proper way. The geographical features of Beijing's spatiotemporal evolution are discussed, and the conclusions may be instructive for spatial optimization and city planning in the future. [ABSTRACT FROM AUTHOR]

In this paper we propose an approach to identify the spatial policy parameters (termed the implementation intensity reflecting planning controls on corresponding spatial constraint) associated with a predefined alternative plan, namely, a predefined-binary urban form. During plan implementation, the alternative plan cannot be fully realized in some cases due to practical urban growth driven by both institutional forces and market incentives, which are comprehensive and complex. Few researchers have investigated spatial policies appropriate for an alternative plan. We aim to propose a novel approach incorporating constrained cellular automata and regionalized sensitivity analysis, a method for global sensitivity analysis to calculate the realization possibility and identify the spatial policy parameters for an alternative plan. This approach is first tested in a virtual space with four predefined urban forms and various point, line, and polygon spatial constraints, with both positive and negative impacts on urban growth. Finally, the approach is also tested in the Beijing Metropolitan Area to identify the required spatial policy parameters for four alternative plans with seven spatial constraints. [ABSTRACT FROM AUTHOR]

The links between urban form and travel behaviour have been widely studied in the field of travel demand management. However, the existing literature is dominated by case studies from the developed countries. A study of a city in a developing and industrialising country can add some fresh evidence to the debate on the impacts of urban form on travel patterns. Using household survey data from Beijing, this paper finds that aspects of urban form have significant effects on workers' car use and the duration of travel by car in journeys to work, while controlling for socio-economic factors and households' preferences related to residential location. The sprawling patterns of land development play a negative role in reducing motorised commuting trips and shortening vehicle hours travelled in the current processes of rapid urban expansion and motorisation. Since urban sprawl is greatly influenced by growing market forces, the findings in this paper reveal the negative effects of regulation-liberation of land development management on travel behaviour modification. [ABSTRACT FROM AUTHOR]

Earth has entered the century of city. Horizontal urban expansion has long been studied and is relatively well understood, but the knowledge of the vertical profiles of built structures remains limited. Here we propose a spatially explicit ensemble model and map the wall-to-wall building height of the three most urbanized Chinese cities in 2017 based on open-access Sentinel-1 SAR data, biophysical indices derived from Sentinel-2 multispectral imageries, and nighttime light (NTL) intensity. We further conduct a chronosequence analysis of the building height for these cities along with their horizontal urban expansion between 1985 and 2017. We show that our proposed method performs well in generating 1 km × 1 km building height maps in Beijing (R2 = 0.87, RMSE = 3.53 m), Shanghai (R2 = 0.82, RMSE = 4.21 m), and Shenzhen (R2 = 0.78, RMSE = 6.92 m). Shenzhen has the tallest (mean building height (MBH) = 37.63 m) and most diverse (coefficient of variation (CV) = 63.84%) vertical landscapes, followed by Shanghai (MBH = 29.86 m, CV= 51.14%). And the vertical profile is the lowest (MBH = 19.21 m) and relatively homogeneous (CV = 44.93%) in Beijing. We also find that vertical urban profiles are coupled with horizontal urban expansion, evidenced by an increase in building height along with the decreasing proximity to urban centers and the increasing urbanization intensity, and a clear imprint of urbanization age in all three cities. The specific characteristics vary among cities due primarily to local urbanization strategies. The knowledge of the vertical profiles of the three most urbanized Chinese cities complements the horizontal insights into urbanization and can assist sustainable land use and urban planning. • Building height of the three most urbanized Chinese cities has been mapped. • Vertical urban profiles are coupled with horizontal urban expansion. • Urbanization age leaves clear imprint on vertical landscapes. • Local urbanization strategies primarily shaped the vertical urban profiles. [ABSTRACT FROM AUTHOR]

Job-housing flows are among the most important travel flows in a city. Therefore, it is essential to measure the extent to which the job-housing flow distribution covers the city space, which can be used as evidence for evaluating the land use status and transportation system. Existing studies have analyzed the spatial distribution of job-housing flows in terms of where and how the flows are aggregated in the city, but they have not revealed the extent to which the flow distribution fills the city space. In this study, we introduce a fractal dimension to measure the space-filling degree of the job-housing flows, which is defined based on the flow space, with the flow being the basic element. Because the flow fractal dimension is independent of the observation scale, we compared the box-counting dimensions of job-housing flows in Beijing and Shenzhen using mobile phone data. The results demonstrated that the fractal dimension was substantially higher in Beijing than in Shenzhen, indicating that the job and home distributions fill more space in Beijing, and the links between the job and home locations are more disordered and irregular in Beijing. These results are related to the more crammed urban land use and higher commuting demand from the suburbs to the city center. • The fractal dimension is used to measure the job-housing flow space-filling degree. • The flows in Beijing and Shenzhen are compared using mobile phone data. • The fractal dimension is substantially higher in Beijing. • New residences or workplaces should be constructed on the existing developed land. • Public transportation networks could be increased to reduce traffic pressure. [ABSTRACT FROM AUTHOR]

Private automobiles have been wildly popular around the world and have transformed the concept of personal mobility for the affluent. However, automobile-oriented development patterns have demonstrably degraded the quality of the city environment. The economic burden of transport infrastructure asset management, plus air pollution, CO 2 emissions and congestion are pressing issues for all cities. City planners struggle with the issues of growth in travel demand and the costs of providing traffic management, parking, policing, and emergency services. The future of personal vehicle mobility and goods movements are particularly challenging, and it is difficult to imagine what the sustainable solutions could be for these wicked problems of transport in megacities. This paper explores urban form, transport activity and quality of life in future cities through the emerging discipline, Transition Engineering. The main methodology is the Interdisciplinary Transition Innovation, Management and Engineering (InTIME) approach, the outcome of which are innovative shift projects that directly step down the negative factors and step up in the quality of life while maintaining the access to social and economic activities. One shift project in Beijing is a new "Work Unit Retrofit" property development enterprise. Integrated land use is a popular idea, but the shift projects in this research answer the questions of "how" the transition to the future city occurs. This research demonstrates the new Transition Engineering approach to sustainable city development that results in actionable property and infrastructure development with financial and social benefits that can be clearly communicated to all stakeholders. • Energy transition to low carbon city • New innovative analysis framework for addressing wicked problems in megacities • Concise way to model commuting trips based on distance distribution • Actionable schemes for future urban sustainable development • New communication tool for decision making regarding urban planning, futuristic cities [ABSTRACT FROM AUTHOR]