Congestion Tolling and Urban Spatial Structure

According to the standard model of urban traffic congestion and urbanspatial structure, congestion tolling results in a more concentrated city. In recent years, a new model of rush-hour urban auto congestion has been developed that incorporates trip-timing decisions—the bottleneck model. In the simplest bottleneck model optimal congestion tolling without toll-revenue redistribution has no effect on trip price because the efficiency gainsexactly equal the toll revenue collected. Optimal congestion tolling then has no effect on urban spatial structure. This paper formalizes and extends this result.     

The Structure and Context of the Urban Growth Coalition

This article examines the perception of local chambers of commerce regarding the urban growth coalition, and compares their observations with those of contemporary urban theorists. The chambers perceive the developmental community as dominated by business groups associated with land-use intensification and by elected officials. The chambers see manufacturing, retail, and service-sector firms as part of a less prominent constellation of developmental actors, and perceive virtually no developmental role for neighborhood or environmental groups.     

20世纪后半期美国大都市区空间结构趋同现象及其理论意义

美国的大都市区化,反映了20世纪世界城市发展过程中不同于传统城市化的新的规律性现象。在这一过程中,大都市区空间结构出现趋同现象,其主要特点是分散化、多中心格局和大规模郊区化。这种现象对传统城市化理论提出挑战,并要求城市化概念的相应调整。在我国部分城市即将进入郊区化快速发展的关键时期,认识到这一点并在相关规划方面做出调整是很有必要的。     

周原空间结构刍议

2004年初始考古学者在周公庙陆续发现了重要的周文化遗址,这些发现为我们从历史地理角度认识周原的空间结构与内涵提供了新的重要线索。周原自古有广义狭义之分,狭义的周原,是太王从豳迁至岐山,在原上所建的都邑及其附近地区。广义的周原应是在太王创业的基础上经古公、季历、文王几代人的建设、发展壮大而成的周人势力范围。广义周原存在两个权力中心区,依据周人政治中心东进趋势、周公庙遗址新材料等分析推理,得出以今岐山北郭乡、周公庙一带为中心的西区应是周人在广义周原范围内最核心区域的结论。     

明清北京城市社会空间结构概说

对明清时期北京城市的社会空间结构进行探讨,是从城市地理学与城市社会学的视角所作的历史研究.从其内部分区的人口密度可以看出,明清时期北京城市在空间上具有一些新的特点,且在不断变化,而这些特点和变化又分别体现在该时期北京的商业空间、居住空间和社会生活与人际交往空间等方面,由此可以使我们更加深刻和全面地了解明清北京城市的发展程度.     

The Geography of Agriculture of Iowa

The following article on lowa's agriculture is of interest because the Soviet Union considers the highly efficient corn-based livestock economy of the state as an example to follow. Khrushchev's campaign to build up a similar Soviet farm economy based on corn, legumes and other high-yielding feed crops is based in part on observations of Soviet agricultural delegations in lowa. The statistical material in the article is based largely on the U.S. Census of Agriculture, 1954, Vol. I, Part 9, Washington, D. C., 1935.     

The Spatial Structure of the Rural-Urban Fringe: a Multivariate Approach

The literature contains many definitions of the rural-urban fringe, but it is difficult to find consensus on how many zones it contains, or how they can be mapped. It is argued in this paper that transitions within the fringe and at its borders are continuous rather than abrupt. In a study area adjoining London, Ontario, cluster analysis is used, and it leads to the identification of three norms. Membership probabilities are then mapped on the basis of each areal unit's resemblance to these norms through discriminant analysis.
Dans la litterature, il y a beaucoup de definitions de la fringe péri-urbaine, mais on discute le numéro de zones dans la fringe et la méthode de sa cartographie. On raisonne ici que les transitions dans la fringe et sur ses bords sont continues plutôt qu'abruptes. Dans cette étude des environs de London, Ontario, on emploie de 'cluster analysis' qui donne l'identification de trois groupes normatifs. On en fait une carte des probabilités d'adhésion sur la base du correspondance de chaque unité aréale à ces groupes normatifs par l'analyse discriminatoire.     

The Spatial Search Problem: Structure and Complexity

The paper discusses structure and complexity of the spatial search problem. From a set of assumptions it derives a rather general version of the spatial search problem and investigates some of its fundamental properties. Most importantly, the paper shows that the decision problem corresponding to the spatial search problem in this general version is NP-complete.     

Substitutability,Spatial Structure,and Spatial Interaction

This paper attempts to distill the relationship among spatial structure, consumer preferences, and spatial interaction. It introduces the notion of substitutability. Destinations are substitutable in both economic-behavioral and physical-locational senses. Inadequate treatment of this can lead to variations in the estimated parameters of conventional spatial interaction models.     

Set-determined Process and the Growth of Spatial Structure

We present an analysis of the effects of different information flow patterns on the growth of spatial structure in a broad class of systems. Examples are drawn from plant and message diffusion processes, the growth of herding in animal populations and, in particular, the evolution of cities in human populations. We model the actions of an “individual” as a response to gradients in a transformation of the “real” space, this transformation being the individual's information map of the space. Interesting deductions occur as a result of allowing the individual's information map to vary from extremely local to extremely global. In the city growth model for example, if migration decisions are based upon extremely local information, then the system is characterized by instability and the lack of any well-defined spatial structure. As the localness of this information map decreases, the system is characterized by the development of well defined spatial structure with a characteristic distance separating the “cities.” In a particular case, we show that the wavelength of the dominant spatial structure is directly related to the size of an individual's information field. These effects are a consequence of interactions between individuals that arise from the nonlocalness of the information fields. We interpret the early growth stages in these models in terms of linear filters.     

The Performance of Policy Networks: The Relation between Network Structure and Network Performance

The importance of policy networks has long been emphasized within the field of policy analysis. However, few attempts have been made to investigate the explanatory power of policy networks using the tools and theoretical concepts provided by social network analysis (SNA). This paper aims to address this need by determining if a relationship exists between the structural features of policy networks, their organizing capacities, and their performance. A comparative case study of four networks within the higher education policy sector confirms the assumption related to the existence of such a relation. It is proposed that an efficient and innovative policy network consists of a heterogeneous set of actors that are centrally and densely integrated. Furthermore, while the level of network heterogeneity is positively related to the function of resource mobilization in the process of policymaking, the level of centralized integration promotes the function of prioritizing. These findings are believed to contribute to our understanding of policymaking in contemporary society. The current paper indicates that a significant explanatory power exists in the concept of policy networks and that SNA is one way of advancing its possibilities.     

近代芜湖城市空间形态演变及其影响因素

晚清至民国初年,随着开埠通商和米市的兴起,芜湖的城区范围也在不断扩展,同时受到地理环境的制约,新拓展的城区主要分布在城西沿江地带,城市空间形态由传统的沿河带状分布演变为以河口中江塔为中心的"L"型新格局,并逐渐向沿江拓展,发展至今,芜湖已是一座名副其实的江城。分析演变过程背后的原因及其关系,发现在近代芜湖城市空间形态演变过程中,"城"、"港"和"市"三者相互依存、相互促进,保持着依存共生的复杂关系,共同推动着近代芜湖的发展,对三者复杂关系的深入探讨,对于近代整个长江沿江开埠城市的研究也有深远意义。     

Markovian Models of Movement Within Urban Spatial Structures

Much work has assumed that movement within urban spatial structures is an “adaptive” process. Nonetheless, mathematical models have not yet been specified and tested which formulate both how different individuals “adapt” over time in destination or route selection, and how predictions about aggregate movement can be derived from postulates about different persons. Two adaptive first-order Markov models for heterogeneous individuals are suggested by the literature. When formulated and tested, however, these models are inadequate to describe travel within urban spatial structures. This implies that the use of Markovian processes to model movement may be overrated. More confidence may be placed in other formulations such as linear learning models of route and destination choice.     

Levels of Spatial Knowledge and Urban Travel Modeling

Models of spatial behavior implicitly assume a direct connection between the individual's utility function and his actual behavior. In reality, this link is mediated by the extent and quality of his spatial knowledge. Without sufficient knowledge, the chosen behavior will be selected from a small number of known alternatives. Using a route choice study in Beer Sheva, this paper investigates the extent and the level of spatial knowledge exhibited by the public in episodic, nonroutine travel. It demonstrates that their knowledge stabilizes at the intermediate “route level,” whereas only professional drivers attain the highest “survey level.” The cognitive opportunity sets of drivers at the route level are idiosyncratic. Accordingly, route selection by the general public was found largely unpredictable. Implications for urban travel modeling are discussed.