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1.
NANCY J. OBERMEYER 《Geographical review》2007,97(3):351-364
ABSTRACT. This article draws from the foundation provided by the ongoing debate about geosurveillance to frame a discussion of the use of tracking technologies in public transit. Specifically, it uses the case of public transit to illustrate the uncomfortable debate about compromises that come with increased surveillance to enhance public safety and security. The article begins with a discussion of the evolution of the debate about geosurveillance, casting the use of surveillance technologies in public transit within this framework. Next, it describes and discusses the implementation of automatic vehicle locators and closed‐circuit television in public transit. The following sections focus on the risks to individual privacy that accompany implementation of these technologies, then describe an unusual effort to draw attention to the prevalence of increased surveillance in public spaces in an effort to expose the risks. The article concludes by making the case that public transit is a place where surveillance provides clear benefits but where the humans who review the surveillance data must interpret and use them responsibly to minimize the risks to individual privacy. 相似文献
2.
Edmund J. Zolnik 《The Professional geographer》2007,59(3):365-377
Using a case study approach, this article explores the potential to increase public transit ridership via the expansion of Unlimited Access (UA) from a university‐ or employer‐based program to a community‐based program. UA partners universities or employers with regional transit organizations to provide free or discounted public transit service to students as well as employees and, potentially, to local community residents. A case study on the only known UA program failure highlights the importance of equitable cost attribution as well as stakeholder coordination and dedicated operations funds to the long‐term success of community‐based UA programs. 相似文献
3.
The relationship between public transit and crime has been extensively investigated for decades. Compared to rail systems, limited research has been conducted on bus transit and its surrounding robbery influence. In particular, most of the studies have focused on either all types of robbery as a whole or street robbery only. Street and off-street robberies have distinct spatial characteristics, however: The former occurs on the street, whereas the latter occurs not on the street but at indoor places or in (semi)public areas. Therefore, they might have different proximity to bus transit. Furthermore, as bus transit is not operated twenty-four hours a day, it is questionable to connect bus transit with robbery when bus transit is not in service. This study uses exploratory spatial data analysis and statistical modeling to compare and contrast street and off-street robberies to discover how their relations with bus transit vary in space and time. Results reveal that both street and off-street robberies decrease as the distance from bus stops increases. Compared to off-street robbery, street robbery is inclined to occur on the street without bus routes and during nonservice hours, respectively. These findings suggest that the preference of street robbery is related to the excess of suitable targets over capable guardians away from bus routes and when bus transit is not in operation, whereas off-street robbery is connected with the residential and commercial attractions along bus routes and people's frequent activities at these places during transit service hours. 相似文献
4.
Tong Zhang Shaoxuan Dong Zhe Zeng Jing Li 《International journal of geographical information science》2018,32(8):1649-1676
The temporal dimensions of public transit accessibility have recently garnered an increasing amount of interest. However, the existing literature on transit accessibility is heavily based on oversimplified assumptions that transit services operate at deterministic speeds using predetermined timetables. These measurements may overestimate transit accessibility, especially for large metropolitan areas where inter- and intra-modal transfers are frequent. To handle travel time uncertainty, a multi-modal transit accessibility modeling approach is proposed to account for realistic variations in travel time and service reliability. The proposed approach is applied to the mapping of transit accessibility in Shenzhen (China), where transit services exhibit significant travel time variations over space and time. Compared to traditional transit accessibility measures, our method has been demonstrated to better capture intrinsic spatial and temporal accessibility variations with complex multi-modal transit networks. Normal distribution of inter-stop travel times and constant travel speed between GPS sampling points are assumed to simply the computation, which we consider to adjust in future studies to better quantify the dynamics of transit accessibility across space and time. 相似文献
5.
城市轨道交通及其沿线土地一体化发展是城市可持续发展的关键问题。提高城市轨道交通可持续性和土地资源配置合理性的关键需掌握轨道交通客流与土地功能之间的依赖关系,而回归分析是研究二者关系的主要方法。既有研究对于土地利用的描述多基于用地面积等概略数据,难以揭示各类属性的用地对客流的影响机理及其空间效应。采用百度地图POI数据以刻画用地信息,提出城市轨道交通车站吸引范围内用地功能的细粒度描述方法,基于全局常参数和局部变参数的回归模型研究车站早高峰出站客流与粗细粒度土地利用的相互依赖关系及其空间效应。针对北京地铁的案例研究表明：车站出站客流与不同功能用地及POI的依赖程度和空间特征存在显著差异。早高峰出站客流更多地受到与就业通勤相关的商业服务业设施用地、公共管理与公共服务用地的影响。在细粒度层面上,出站客流对写字楼和政府机构的依赖性更大,二者显著分布在就业岗位密集的中心城区功能分区和城市核心区。基于细粒度POI的局部变参数模型能较好地识别各类土地利用对车站客流的影响及其空间异质性,案例研究表明车站客流与土地利用的依赖关系是各类属性功能用地影响及其空间效应的叠加。 相似文献
6.
Many Chinese cities are in a transition from industrial to post-industrial urban economies. In this process of urban restructuring, land use becomes polycentric and fragmented. More sophisticated models are needed to estimate the amenity effects of this complex residential environment. This article assesses the relative housing price effects of neighborhood characteristics and accessibility in Nanjing, China. This is achieved with a hedonic price model that incorporates detailed spatial measures, geographical contingency, and a modified version of Alonso’s (1964) general theory of land rent. A crucial finding is that the effect of job accessibility on house price varies depending upon the specific sector of employment. Accessibility to jobs in the public and private service sectors has strong positive effects. However, housing proximity to heavy industries has a spatially nonlinear effect: negative in close proximity, but positive at a larger distance. Second, when we control for job accessibility, access to public transport has an added positive effect. Finally, neighborhood “quality” (defined in terms of nearby amenities) is also relevant, but far less than access to service employment. This research shows that Nanjing’s housing prices are affected by different residential characteristics than those with dominant price effects in Western cities. 相似文献
7.
《Urban geography》2013,34(2):139-172
Although welfare rolls have dropped considerably in recent years, most welfare recipients who find work are employed in low-wage, insecure jobs. The problem of "working poverty" is especially acute in large city-regions such as Los Angeles, where local labor market restructuring has created an expanding, low-wage economy, increasingly dependent on immigrant labor. This paper analyzes the employment outcomes of 6,931 women who completed the county's welfare-to-work program in 1996. I evaluate their earnings, labor market segmentation, and job stability. The results show that women were highly concentrated in low-wage service jobs and experienced high levels of turnover and unemployment. Many were unable to obtain employment in the formal labor market. I argue that the struggles of the working poor in a growing regional economy are explained not solely by human capital limitations, but by processes of local labor market restructuring that have contributed to widespread economic insecurity in Los Angeles County. 相似文献
8.
Michael J. Widener 《The Professional geographer》2017,69(3):362-371
Research on access to healthy foods often emphasizes the spatial proximity of residents to food stores like supermarkets as a way to gauge overall accessibility. Much of the literature has focused on locating the closest facility, assuming that access to one food store is sufficient. Given evidence that access to multiple healthy food stores can improve diets, however, this article examines how closest facility measures differ from cumulative opportunity accessibility measures across space in a medium-sized U.S. city. Differences in access between automobile and transit riders, using realistic travel time costs, are also considered. Results demonstrate that the two types of accessibility measures produce different accessibility geographies and that there are disparities in access for those dependent on transit. These findings indicate that researchers should carefully consider whether access to one supermarket opportunity is enough and pay special attention to the mode residents rely on to access food. 相似文献
9.
Matthew Wigginton Conway Anson F. Stewart 《International journal of geographical information science》2019,33(9):1759-1787
Most analyses of accessibility by public transit have focused on travel time and not considered the cost of transit fares. It is difficult to include fares in shortest-path algorithms because fares are often path-dependent. When fare policies allow discounted transfers, for example, the fare for a given journey segment depends on characteristics of previous journey segments. Existing methods to characterize tradeoffs between travel time and monetary cost objectives do not scale well to complex networks, or they rely on approximations. Additionally, they often require assumed values of time, which may be problematic for evaluating the equity of service provision. We propose a new method that allows us to find Pareto sets of paths, jointly minimizing fare and travel time. Using a case study in greater Boston, Massachusetts, USA, we test the algorithm’s performance as part of an interactive web application for computing accessibility metrics. Potential extensions for journey planning and route choice models are also discussed. 相似文献
10.
城市常规公交空间演化过程研究——以广州市为例 总被引：1，自引：1，他引：0
以广州市为例,从公交覆盖度、线网密度和覆盖效益3个方面考察广州市常规公交的空间演变特征,结合趋势外推法,预测广州市未来公交发展态势,总结常规公交空间演变规律。研究发现：① 建国以来,广州市内的常规公交经历了由“低效公平”的低级均衡向出行效率变高、公平性变低的转变,随后又出现了非均衡状况缓解、公平性上升的状态;② 结合对未来发展的预测,发现它有由低级均衡向高级均衡状态演变的趋势。比较广州在城市发展中所处的阶段,可以推论中国类似于广州这样发达的超大城市,市内公交状况大多处于上述演变过程的后半期,而大多数城市则处在这一演变过程的前半期。 相似文献
11.
Luke David VanLandegen Xuwei Chen 《Applied geography (Sevenoaks, England)》2012,32(2):787-797
Public transit plays an important role in emergency evacuations, particularly for areas where public transit serves as a major commute mode for commuters. Microsimulation techniques provide great flexibility in assessing different scenarios in emergency situations. Combining GIS-based network analysis with microsimulation techniques, this study developed a framework to simulate emergency evacuations using rail transit. Applying the framework to a hypothetical attack on the Pentagon, this study investigated the performance of the Washington Metropolitan Area Transit Authority’s Metrorail for large-scale evacuations. A network-based analysis was performed to estimate the number of riders in association with each metro line and station. Using VISSIM, a multi-mode micro-simulation software package, this study integrated a pedestrian model with a Metrorail transit model to evaluate the performance of the Metrorail in the hypothetical evacuations. The simulation results suggested that if the potential of Metrorail transit is effectively utilized, it could be very useful resource during a large-scale evacuation. This study demonstrated the great potential and flexibility of microsimulation techniques for evaluating complex evacuation scenarios and strategies. The framework and approach used in this study can be applied to analyze other similar situations and help develop effective evacuation plans. 相似文献
12.
北京公交就业可达性及其地区和人群差异 总被引：2，自引：0，他引：2
运用经济普查、人口普查数据和基于百度地图的公交出行时间数据,分析北京都市区基于公共交通的就业可达性及其在城市不同人群和地区间的差异。结果表明：北京都市区的居民可在60分钟内通过公共交通到达18.3%的都市区工作岗位,这比美国100个最大的都市区的平均就业可达性水平要高,接近于美国纽约都市区的就业可达性水平。同时,由于就业郊区化程度有限和以中心—放射式布局的公交网络,北京都市区内的公交就业可达性存在着巨大的区域差异,中心城区的就业可达性远远高于郊区。此外,人口居住的郊区化程度远远高于就业的郊区化程度,导致北京都市区宏观层面的职住不平衡。随着人口居住郊区化程度的提高,公共交通如何服务居住日益分散的人口,提高就业可达性,是一项巨大的挑战。研究还发现,由于城市中心区的大部分就业为高技术的就业岗位,因此高受教育程度人口能更多地享受目前公共交通系统的便利,而受教育程度低的人口和外来人口公交就业可达性较低。为解决弱势群体所面临的就业可达性的不平等问题,需要更多的规划与政策干预。 相似文献
13.
Eliahu Stern 《The Professional geographer》1980,32(3):326-334
The degree to which people judge the change in transit service level as service connectivity changes is assumed to vary with total transfer waiting time. An experiment was devised to collect measures of cognized connectivity of intercity transit services in relation to transfer time, and cognitive scalar values were consequently derived. An inverse relationship was found between cognized service level and connectivity; cognized transit level decreased at a decreasing rate. An analysis of the bus-service network in the Israeli Galilee region suggests the appropriateness of cognitive scalars for measuring the internodal accessibility of public transport services. 相似文献
14.
中国都市圈中运量型轻轨交通的发展问题研究 总被引：6，自引：0，他引：6
从都市圈的空间结构和交通需求的特点分析入手,讨论了中运量型轻轨交通在都市圈公共交通中的地位与作用。结合中国都市圈建设中有关轻轨公共交通发展的问题,指出发展以中运量型轻轨交通为骨干的城市公共交通是中国都市圈交通建设的重要方向,并对中国都市圈以中运量型轻轨交通为骨干的都市圈综合交通体系的规划建设提出了若干建议。 相似文献
15.
《Urban geography》2013,34(8):1018-1038
Working-poor women face many challenges in their quest for economic self-sufficiency. Although welfare reform promises jobs, women do not have equal access to necessary services, including transportation. With the 2010 reauthorization of TANF (Temporary Asssistance for Needy Women), there is a need to develop a methodology that uses qualitative individual-level data to evaluate whether public transportation will serve working-poor single mothers in this quest for self-sufficiency. Using ethnography, travel diaries, and a GIS for a sample of women in the process of leaving welfare in Knoxville, Tennessee, travel behavior is examined both qualitatively and quantitatively in order to understand why they rarely use public transportation. Further research into the ways these women move around in a sprawling, medium-sized city reinforces and seeks to understand the extensive social networks working-poor mothers rely on. These women create communities of spatial necessity, bartering for basic needs to overcome transportation constraints. 相似文献
16.
《The Professional geographer》2013,65(3):326-334
The degree to which people judge the change in transit service level as service connectivity changes is assumed to vary with total transfer waiting time. An experiment was devised to collect measures of cognized connectivity of intercity transit services in relation to transfer time, and cognitive scalar values were consequently derived. An inverse relationship was found between cognized service level and connectivity; cognized transit level decreased at a decreasing rate. An analysis of the bus-service network in the Israeli Galilee region suggests the appropriateness of cognitive scalars for measuring the internodal accessibility of public transport services. 相似文献
17.
优先发展公共交通是解决我国城市交通问题、实现城市交通可持续发展的必由之路。在我国社会经济发展的新阶段,公交优先对落实能源战略、促进环境保护、集约节约用地、建设低碳城市具有重要意义。通过解析新加坡常规公交系统的成功经验,探求其对我国城市常规公交系统新一轮发展策略的有益启示,以期为我国城市交通的进一步跨越式发展提供参考依据。 相似文献
18.
How do changes in the daily food and transportation environments affect grocery store accessibility?
A healthy food environment is an important component in helping people access and maintain healthy diets, which may reduce the prevalence of chronic disease. With few exceptions, studies on healthy food access in urban regions typically ignore how time of day impacts access to food. Similarly, most extant research ignores the complexities of accounting for the role of transportation in spatial access. Examining healthy food access is important, especially for populations whose day-to-day schedules do not align with a typical work schedule. This study profiles novel methods that can be used to examine the daily dynamics of food access in Toronto, Ontario, using grocery stores as a case study to examine the changing geographies of food access over a 24-h period, and the impact of a changing public transit schedule on food access. Walking and automobile travel times are also reported. Results indicate that access to grocery stores is severely diminished for large parts of the city in the late night and early morning, and that public transit travel times are higher and more variable in the early morning hours. Ultimately, this research demonstrates the need for further study on how residents with nonconventional schedules experience, and are affected by, the dynamic food and transportation environments. Future research should build upon the methods presented here to include a broader range of food retailers. 相似文献
19.
城市交通、土地利用和城市空间结构的相互关系一直是城市地理学、城市规划学和交通地理学研究的核心问题。大容量公共交通、混合型土地开发、宜人的步行环境和高质量的公交服务是公交导向型开发(TOD)模式的主要特点。本文分析了TOD对城市土地利用和城市空间结构的作用机理发现:土地开发强度、土地利用结构以及土地价值是TOD影响城市土地利用的3 个主要方面,而TOD对路网结构、城市规模和城市空间布局的作用进一步影响城市空间结构及其演化。进一步研究发现:大容量公共交通的建设使得城市竞租曲线和开发密度具有多波峰的特点,遵循"随着时间的变化从城市中心向外围递减"的规律。基于中外城市发展背景差异,本文从宏观、中观和微观3 个层面提出建立以大容量公共交通为主轴、以TOD站点为枢纽的轴辐网络状城市空间结构,并提出了TOD站点开发的距离、级差密度、多样性和设计的4Ds原则。 相似文献
20.
Itzhak Benenson Eran Ben-Elia Yodan Rofé Dmitry Geyzersky 《International journal of geographical information science》2017,31(2):213-236
Accessibility is an important consideration in sustainable mobility policies, particularly for transit users. Measures suggested in the literature are based on coarse aggregate spatial resolution of traffic analysis zones that is sufficient for managing car travels only. To reflect a human door-to-door travel, transit accessibility demands an explicit view of the location of origin, transit stops and destination, as well as of the temporal fit between transit lines timetable and traveler’s needs. We thus estimate transit accessibility based on mode-specific travel times and corresponding paths, including walking and waiting, at the resolution of individual buildings and stops. Car accessibility is estimated at a high resolution too. A novel representation of transit network as a graph is proposed. This representation includes all modal components of a transit travel – walking, waiting at a stop, transit ride, transfers between lines, thus enabling unified view of a travel, regardless of mode. The use of modern high-performance graph database allows construction of high-resolution accessibility maps for an entire metropolitan area with its 100–200 K buildings. The application is tested and applied in a case study involving the evaluation of the 2011 bus line reform in the city of Tel Aviv. Specifically, we demonstrate that while the reform increased the average accessibility for the entire city the increase was not uniform with different areas of the city experiencing different absolute accessibility by transit and relative accessibility in comparison to car travel. The bus reform did in fact benefit travelers that experienced low relative accessibility, but the benefits are mainly accruing to longer trips. Our approach and computational methods can be employed for directly investigating the impacts of transportation infrastructure investments. 相似文献