Physical accessibility as a social indicator

A discussion is presented of the ways in which accessibility to employment and urban services constitute an important measure of the quality of urban living, and how accessibility might, therefore, be included as an important component of a “social report” for a city or region. A conceptual framework is introduced for measuring accessibility in terms of the ease with which citizens may reach a variety of opportunities for employment and services. This framework is interpreted as an approach to evaluating transportation and regional plans which differs from approaches based upon travel volumes and travel times which are currently employed in urban transportation planning and evaluation. The use of the proposed measures of accessibility is illustrated with data on accessibility to employment and health care facilities in Los Angeles, and these data are interpreted to illustrate differences in accessibility as a function of spatial location of residence, and socio-economic status.     

Intraurban variation in the price of housing

Theoretical models of spatial consumer behavior assume the existence of a housing price surface that increases with accessibility. It is often hypothesized that inadequate accessibility measures are responsible for the failure of most empirical studies to support this premise. A general accessibility measure consisting of a double power series in cartesian coordinates is developed and shown to represent a general formulation of traditional accessibility measures. This formulation is incorporated in a hedonic price regression model, and the model is estimated using census tract data for the city of Milwaukee. The hedonic prices are then used to construct intraurban housing price indexes. The results of this study provide strong support for the existence of the presumed price surface. A comparison of this new hedonic price model with traditional models suggests that the double power series formulation is a superior representation of accessibility.     

Rent Capitalization and Transportation Infrastructure Development in Jakarta

Using Jakarta, Indonesia as a case study, we evaluate the degree to which proximity to freeway interchanges gets capitalized into office rents, controlling for factors like regional accessibility. The research shows strong capitalization effects, with rent premiums decaying exponentially with distances from freeway access points. It also shows that office rents are a stronger function of distance to Jakarta's historical center, Monas, than a gravity-based measure of accessibility to upper-income households. Thus, a monocentric measure of location explained variation in office rents better than a polycentric measure of proximity to labor markets. While value capture principles are attractive in theory, implementation is particularly difficult in developing countries like Indonesia. Jakarta's own betterment tax program has been plagued by poor administration and enforcement. We argue that shifting betterment tax financing away from a focus on residential properties to high-end office and commercial land uses would likely yield higher rates of return and be far easier to implement.     

Improving spatial accessibility to regional health systems through facility capacity management

In austerity times, the general interest to reduce costs and improve efficiency levels often resulted into local cuts to public expenditure and profound reorganizations of existing service networks, especially in sectors like healthcare. In Italy, a recent reform prescribed the reconfiguration of time-dependent (i.e. emergency) hospital networks with the aim of improving patients’ accessibility conditions. In order to evaluate the impacts determined by this reorganization, we perform a spatial analysis in which we consider the distance from the closest facility as an accessibility measure. Results obtained from the spatial analysis confirm that users effectively benefit from the reorganization process but also that further improvements are possible, especially for the worst served ones. To this end, we also propose solving a mathematical programming model aiming at redistributing the capacities, i.e. the supply of beds, among the hospitals of the network seeking to maximize users’ accessibility. The realized computational experiments show that averagely better and even more equitable accessibility conditions could be obtained by containing the deriving reorganization costs.     

Urban agglomeration economies in a Linear City

A model of firms' spatial allocation and location is developed by explicit incorporation of urban agglomeration benefits using accessibility measure. In a linear and one-activity city, each firm is assumed to interact with each other for face-to-face transactions, and the unit construction cost of office building is considered to be proportional to firm density. It is shown that both the optimum and the equilibrium distributions of firms are cosine, quadratic or cosine-hyperbolic curves, that the latter is more dispersed, and that the equilibrium rent function is concave near the city center and convex near the boundaries.     

中国大城市交通问题及其发展政策

本文分析了中国城市化与城市机动车增长所带来的大城市交通问题的性质。提出大城市的交通规划和管理应把机动性和可达性有机结合起来。一是积极鼓励发展大容量的城市快速轨道交通系统 ,使之成为大城市交通的主骨架 ;另一是采取有效的政策措施 ,引导大城市中心产业向外扩散 ,减轻市中心区的交通和环境压力 ,积极推动多中心网络城市的发展。     

Planning for equal transit-based accessibility of healthcare facilities: A case study of Shenzhen,China

Recent location-allocation studies have made considerable progress in optimizing the equality of facility accessibility but are focused on automobile transport to facilities. In cities, however, the transit-based accessibility of essential services is crucial for social equality and sustainable development. In this study, we develop a modified transit-based maximal accessibility equality (MAE) model for optimizing the equality of the transit-based accessibility of healthcare facilities. In this model, equality is quantified as the weighted mean absolute deviation (WMAD) of accessibility across locations. Two scenarios are set up to reallocate resources or allocate newly added resources. The results reveal that the equality of transit-based healthcare accessibility can be significantly improved in both scenarios. A dispersed planning strategy for facilities is suggested to achieve equal accessibility. However, the transit-based optimization results significantly differ from the car-based optimization results, with more supply allocated to facilities close to transit corridors. This finding implies that the traditional car-based MAE model might generate unequal healthcare accessibility for transit-dependent populations and thus lead to biased recommendations for healthcare planning. Furthermore, it shows that traditional car-based optimization may engender a misallocation of healthcare supply, exacerbating the inequality in healthcare accessibility. The necessity of incorporating public transit into public facility planning is highlighted. The improved MAE model can be applied in cities where the supply of public services is relatively adequate and public transit plays an important role in daily mobility.     

Measuring the spatial accessibility to fire stations using enhanced floating catchment method

Enhancing the spatial accessibility of population to fire services is a key strategy to help improve emergency response, minimise property loss, and reduce injuries and deaths. Given its significance for fire service policy and strategic planning, we draw on small area population forecasts, fire station locations and the road network, and employ the enhanced two-step floating catchment method to compute the levels of spatial accessibility of population to fire services in relation to current and future population growth in Brisbane, Australia. Results show that lower levels of spatial accessibility to fire services exist in the most populated areas compared to those that are least populated. Further, we reveal that some areas are more likely to suffer a reduction in spatial accessibility than others. Spatial accessibility of population to fire services over the period to 2036 is likely to reduce as a consequence of rising demand for service. The identification of locales that experience lower levels of accessibility to fire services will enable fire services agencies to strategically plan infrastructure investment and help enhance the operational efficiency of emergency response.     

城市可达性研究的理论与方法评述

首先探讨了可达性的涵义与主要特征.其次综合可达性的主要定量评价方法,对各种方法的优缺点进行比较,并总结了近期可达性评价方法的进展情况.最后对可达性研究中存在的问题进行了探讨.     

Accessibility Changes and Urban House Price Appreciation: A Constrained Optimization Approach to Determining Distance Effects

Land use and location theory suggests that accessibility is an important determinant of residential land values, and of changes in those values. This study explores the construction of the Dames Point Bridge over the St. Johns River in Jacksonville, Florida, to examine the impact of changes in accessibility on housing values. Benefits to the north, from increased accessibility from the urban perimeter, are of primary interest. Additionally, dis-benefits to the south, (from increased traffic congestion and crime), are also investigated. A constrained optimization approach is used to determine the extent (distance from the bridge) to which changes in accessibility benefits or dis-benefits are reflected in urban house price appreciation.     

Political determinants of fiscal transparency: a panel data empirical investigation

The investigation of the determinants of fiscal transparency has been mostly performed on cross-sectional data, and it has produced mixed results. This paper improves the existing literature by performing a static and dynamic panel analysis of the effect of a set of political variables on the level of fiscal transparency in 36 democratic countries. By using a recent measure of fiscal transparency based on IMF Governance Finance Statistics and available from 2003 to 2013, we find strong links between political environments and the dynamics of fiscal disclosure. Our results show that government control over the legislature exerts some negative effect on fiscal transparency, while the effect of government ideology is shown to be at least fragile. Furthermore we find that legislature fragmentation exerts a negative effect on fiscal transparency, which suggests that competition within the parliaments does not increase fiscal transparency, but instead it induces governments to react by reducing accessibility to information.     

THE EFFECT OF KNOWLEDGE ACCESSIBILITY ON INTERNATIONAL INCOME INEQUALITY

Using a structural model of new economic geography, we estimate the effect of accessibility to foreign knowledge on international income distribution. Whereas previous literature has mainly focused on the importance of geographical accessibility to foreign markets, this paper emphasizes the role of accessibility to foreign knowledge in determining international income inequality. Using cross-country data of income per worker, bilateral trade flows, and number of flight passengers, we find evidence that the accessibility to foreign knowledge raises per capita income significantly.     

Incorporating activity space and trip chaining into facility siting for accessibility maximization

Location models have been widely used to support locational decisions for various service provision. One common objective of location models has been to ensure maximal accessibility of sited facilities to demand populations. Accessibility evaluation in location models often assumes that trips originate from fixed locations (usually home) and are single purpose. These assumptions contradict the empirical evidence that suggests trips also commonly originate from non-home locations and may involve multiple stops. In this study, a new multi-objective location model is developed that extents the classic p-median problem (PMP) to account for a more realistic assessment of accessibility. Based on the individual accessibility assessment, notions of trip chaining and activity space are incorporated into the model development. In addition to fixed home locations, stops along chained trips are allowed for potential service site visits, and activity space is introduced as an additional dimension to evaluate accessibility of alternative opportunities. The effectiveness of the new model is demonstrated using an application in Tucson, AZ.     

EFFECTS OF PUBLIC TRANSIT ON AUTOMOBILE OWNERSHIP AND USE IN HOUSEHOLDS OF THE USA

This study develops econometric models to predict the effect of access to and distance to public transit on automobile ownership and miles driven. Ordered logit model is used for automobile ownership and multiple regression model is used for vehicle miles traveled (VMT).
Inverse square root of transit distance is used as a measure for transit accessibility. Important findings in the analysis are (i) the number of licensed drivers is the primary determinant of the number of automobiles owned, (ii) the presence of children is not a significant factor in automobile ownership and VMT, and (iii) the VMT of multi-vehicle households is more sensitive to transit than one-vehicle households. Transit simulations are performed by improving the distance to and access to public transit. The results showed that total VMT in National Ambient Air Quality Standard non-attained metropolitan statistical area is reduced by 11% (approximately 60 billion miles) with 0.1 miles simulation.     

福建省公路网可达性研究

基于福建省区域系统的开放性,以县域为研究单元,采用平均旅行时间指标,利用TransCAD软件对福建省公路网的可达性进行计算,并分析可达性空间格局的特征。     

长江中游城市群空间结构效益比较与优化研究

基于OpenStreetMap公路路网和社会经济数据,利用可达性分析及空间相互作用引力模型,从规模效益、距离效益、空间联系效益3个方面对2017年长江中游城市群的空间结构效益进行比较分析。研究发现:武汉城市圈城市紧凑度高,平均可达性最好,内部联系强度大,空间凝聚力强;长株潭城市群在人口及经济规模上具有明显优势,中等联系层面网络趋于完善,一体化程度高,但空间可达性差;环鄱阳湖城市群综合竞争能力弱,空间联系松散且较弱,但空间可达性较好。未来,长江中游城市群的发展可以从重构区域发展空间结构、加强不同等级规模城市梯度建设、构建综合交通运输网、建立区域发展协调机制和促进产业生态绿色发展等方面寻找着力点。     

The spatial dimensions of accessibility to general hospitals in rural Nigeria

The problem of inadequate health services in rural Nigeria is worsened by poor location decisions which have resulted in various degrees of inaccessibility to the existing health facilities. In this paper, some accessibility treasures are applied to determine the spatial variation of access to general hospitals in the rural Anambra State of Nigeria. The local government area (LGA) is used as the spatial unit of analysis and the spheres of influence of the general hospitals located in each LGA are measured using three indices of accessibility. The scores for each LGA are aggregated and classified according to the levels of accessibility using a cluster analysis technique. The emerging clusters are briefly examined and a needs assessment of all the LGAs for general hospitals is carried out. Based on this assessment. the minimum number of general hospitals required in each LGA to effect an equity of access is suggested. Possible advantages accruing from this allocation procedure are presented and their policy implications discussed.     

Measuring Accessibility of Housing to Public–community Facilities Using Geographical Information Systems

This paper examines housing accessibility to public–community facilities (PCFs) using geographical information systems (GIS) for four county–wide metropolitan areas in North Carolina with population ranging from 90,000 to 700,000. An optimization–based assignment model is developed and implemented in ArcView GIS. Rather than using the conventional and less accurate traffic analysis zone (TAZ) or census geography, this research uses detailed county–wide building and parcel databases to estimate direct distances, hence accessibility, from homes (i.e., apartment, manufactured home, and single–family house) to PCF (i.e., office, shopping center, school). The results indicate that distinct housing accessibility patterns exist. In general, multi–family housing such as apartment and townhouse enjoys higher accessibility to positive (desirable) PCFs, followed by single–family detached housing. Manufactured housing has been placed further away from most positive PCFs, but closer to some negative (undesirable) ones.     

城市交通与城市空间演化相互作用机制研究

认为城市交通与城市空间演化之间存在着持续的相互作用关系:一方面,城市空间演化不断对城市交通提出更高的要求,并为城市交通的发展提供相应的条件;另一方面,交通可达性的提高和交通方式的变革又会对城市空间的进一步演化产生引导作用,它们之间通过可达性这一关键因素的不断调整和变化实现相互促进和共同发展.     

Improving accessibility to rural health services: The maximal covering network improvement problem

Accessibility to health facilities is a critical factor in effective health treatment for people in rural areas of lesser-developed countries. In many areas accessibility is diminished by the lack of all-weather roads, making access subject to weather conditions. Location-allocation models have been used to prescribe optimal configurations of health facilities in order to maximize accessibility, but these models are based on the assumption that the underlying transport network is static and always available. Essentially, past work has ignored the potential impacts of improvements to the transport system in modeling access. In this paper we propose a model that treats the opposite side of the location/transport equation; that is, a model that treats existing facility locations as fixed and improves health service accessibility by upgrading links of the transport network to all-weather roads. This new model, called the Maximal Covering Network Improvement Problem (MC-NIP) is formulated as an integer-linear programming problem. An application of the MC-NIP model to the Suhum District of Ghana is presented, which shows that even a modest level of road improvement can lead to substantial increases in all-season access to health service.