Dissertationen zum Thema „Measuring accessibility“

In recent years, spatial data derived from cell phones has become increasingly recognized as a valuable data source for urban analysis. Using a sizeable dataset depicting the physical movements of several million Swedish and Danish cell phones during 24 hours, an analysis of aggregated individual mobility levels and mobility patterns is conducted. The analysis covers two measurements of mobility, total diurnal mobility and commuting mobility. Findings indicate that phone data may provide seminal insights on otherwise scarcely accessible information on how space is experienced and interacted with depending on the individual's residential location. The data is analysed using a broad set of spatial analysis techniques incorporating both statistical and visual representations of spatial mobility and spatial relationships.

This study combines a literature search and review with a real-world survey to identify, compare, and contrast techniques of measuring accessibility in conceptual and operational terms. An hypothesis-based approach is employed to ascertain how these techniques are used in the public and private sectors. With emphasis on the spatial dimension of accessibility, the thesis examines the definition of accessibility, the relative use of different accessibility measurement techniques, and the units used to measure spatial separation. The thesis also explores barriers to accessibility, the criteria and relative importance of spatial and aspatial factors in making location, network and routing decisions, and the use of GIS to implement accessibility measurement techniques. Results suggest that, despite differences in goals and/or objectives, there are similarities between the public and private sectors in both the conceptual and operational aspects of accessibility measurement, the criteria used to make location and transportation network decisions, and the limited use of Geographic Information Systems (GIS) to implement accessibility measurement techniques.

Satisfactory public transportation (PT) should enable people to reach attractive destinations and desired activities fast, comfortably, safely, and affordably. When PT fails to do so it will have negative effects on the overall accessibility in a society. Evaluating a PT system essentially means measuring to what extent the demand from the users is met, and for such an analysis understanding the concept of accessibility is paramount. Whether an individual will experience a high or a low level of accessibility will likely depend on their personal capabilities, as well as on the surrounding environment. Barriers obstructing an individual from using PT could for example be of physical of phycological nature or come in the shape of public space management disproportionally favoring certain groups of society. Low accessibility can thus be linked to social exclusion, since when a person cannot reach important destinations, their chances to participate in society will be subdued. To measure the accessibility of a PT system, and how a PT system affects the overall accessibility of a destination, it is common practice to use indicators that can represent different categories of social exclusion. This approach was the basis for constructing the performance measurement tool called Bus Stop Ranking Algorithm (BSRA) which was created in the QGIS application Graphical Modeler. BSRA calculates the usefulness of bus stops by counting the number of vulnerable groups, the number of workplaces, and the total population within comfortable walking distance from bus stops, as well as comparing travel times by car and bicycle from residential areas to important locations. The tool was ordered by a private PT company which will use it to make decisions regarding e.g., creating new bus stops, or for relocating, removing, or redesigning existing bus stops or bus routes. The Swedish municipality Lidingö was used as the study area to demonstrate how to use BSRA and how to interpret its output. Using equal weights for all indicators, it was discovered that 9 bus stops in the southern part of Lidingö could be regarded as particularly useful compared to the other 207 bus stops in the municipality. Variables such as the space-temporal component, i.e., changes during the day were not used. Socio economic factors such as segregation were also not highlighted, since all indicators had the same effect on the total scores. Adjusting the weights for some indicators could expose underlying dynamics affecting the total scores for the bus stops and help the PT company make design changes where they will be needed the most.

In the Tampa Bay region, increasing population and changing demographics have begun to alter the characteristics of established neighborhoods. An increase in suburban growth has triggered a shift in the location and profitability of food establishments in socially disadvantaged neighborhoods. Supermarket closures have garnered attention from public health officials who are concerned with the overall availability of fresh food throughout Hillsborough and Pinellas Counties. Unfortunately, there has been little research surrounding the quality of food sold at establishments in both the Tampa Bay region and abroad. Instead, many geographic studies have chosen to group both fresh and prepared food establishments into a singular category for analyses. While helpful for a generalized understanding of food access overall, these methods do little to convey access to fresh foods which are essential for a balanced diet. This study offers a different perspective from traditional food access studies by categorizing food stores into fresh and prepared categories. For each food category, the Cumulative Opportunity Measure (COM) was first applied to measure food accessibility at the census block group level; a descriptive analysis was then employed to examine the relations between food accessibility and socioeconomic variables. In order to provide a meaningful comparison, these same steps were taken to emulate the results of the combined model (fresh and prepared) that is often utilized in previous studies. Finally, a map displaying the COM ratio of fresh to prepared food by block group was created to highlight areas with disproportionately more fresh (or prepared) food opportunities. Results indicate that rural may be at a disadvantage with respect to fresh food accessibility. Also, a discrepancy between the fresh model and the prepared and combined models, in relation to female headed households, may indicate that food establishment classification has a significant effect on food accessibility. Overall, positive relationships were observed between factors relating to minority status, no GED, room occupancy, public assistance, limited English, poverty, and lack of vehicle ownership for the fresh, prepared, and combined food accessibility models. Finally, the ratio of fresh to prepared food establishments could explain why some populations exhibit higher rates of obesity even when in direct proximity to fresh food opportunities.

The growing concern for the shortage of primary care physicians (PCPs) prompted a government legislation to designate areas where shortage in the delivery of primary care services occurs. The implemented systems (e.g., HPSA, MUA, and MUP) analyze utilization of health services within confined administrative units and fail to account for spatial interactions that occur across administrative borders. This research examines the spatial accessibility to PCPs and the underlying demographic and socioeconomic settings. With the Nashville Metropolitan Statistical Area (MSA) as a study area, this study utilized data from the U.S. Census 2000 and 2010, as well as the known locations of (PCPs) collected in 2010. Geographic Information Systems (GIS) provided the tools by which the processing and analysis of the data was carried out. Specifically, network analysis was applied to estimate travel time and service area coverage. A Two-Step Floating Catchment Area (2SFCA) method was implemented to measure spatial accessibility to PCPs. This method was applied to measure accessibility at the level (census block) that most accurately represents the spatial population of the Nashville MSA. In addition, this research implemented several distance-decay functions in addition to the dichotomous function of the standard 2SFCA method. This research has found that the majority of the population residing in the Nashville MSA enjoyed good spatial accessibility to PCPs. However, the highest percentages of those resided in areas of low accessibility were located in periphery rural areas as well as isolated areas poorly connected to the roadway network due to certain physical barriers such as lakes and streams. Moreover, this research has found that, in general, non-spatial factors intensified the most where there was good accessibility to PCPs.

Accessibility is an enduring concept in Transport Planning, historically relating to the performance of the transport system and more recently to the understanding of social aspects of transport planning and practice. Accessibility Planning, set in the context of addressing social exclusion, is one example of an applied approach to accessibility which seeks to reflect user perspectives. However, translating the concept into practice is problematic. Measurement is dominated by time and distance and separation of people from destinations, rather than reflecting individuals’ perceptions. The core aims of this thesis are to critically appraise dominant approaches to Accessibility Planning and to understand how objective measures relate to perceptions of accessibility. The thesis is structured into two main empirical stages. Firstly a review of current approaches is undertaken through engagement with accessibility practitioners in England and a comparative analysis of accessibility measures in the English Core Accessibility Indicators and National Travel Survey. Secondly a mixed methods case study, utilising household survey and mental mapping interviews in Greater Nottingham, is presented. Statistical analyses are used to compare objective and self-reported measures of accessibility and to explore factors contributing to perceptions of accessibility. Perceived accessibility is more strongly related to selfreported measures than to objective measures. Demographic characteristics and attitudes are also important in explaining variation in perceptions. For example, while an elderly person may perceive accessibility to be worse because of physical mobility issues, car users may perceive inaccessibility due to lack of awareness of alternatives, leading to different policy approaches. A grounded theory analysis of interview data highlights that affective and symbolic factors are useful in understanding perceptions of accessibility, in addition to the instrumental factors more usually studied. Recommendations include a need to incorporate subjective measurement alongside more traditional accessibility measures, in line with wider policy discourses such as the recent development of subjective wellbeing measures by the Office for National Statistics.

Master of Regional and Community Planning
Department of Landscape Architecture/Regional and Community Planning
Jason Brody
Recent research has focused on assessing equity with regards to location of public services and the population served. Instead of equality, equity involves providing services in proportion to need, rather than equal access for everyone. This study uses three commonly identified measures of accessibility (minimum distance, travel cost, and gravity potential) to assess how equitable higher-need residential populations of Kansas City, MO are served by neighborhood parks. Using Census 2000, socio-economic block group data, areas with high population concentrations of African-American and Hispanic populations, as well as areas of high density and low income are characterized as having the most need. However, correlations of higher-need populations with the accessibility measures reveal patterns of equity within the Kansas City. MO study area. Results indicated that while most of the high need population was adequately and equitably served by neighborhood parks, there were still block groups that did not have access to this type of public resource. This research follows methods proposed in previous studies that utilize the spatial mapping and analysis capabilities of ArcGIS and promote the use of these tools for city planners and future park development and decisions.

Food security in urban environments is becoming an increasingly important issue worldwide; urban expansion and urban infilling means that city populations are rising while the amount of available land for growing food is reducing. Accessibility of food, in regards to potential food growing space and food retail locations at the household level, is a key indicator for determining how resilient households are to food insecurity. This thesis investigates accessibility of food in urban environments, and a methodology has been developed that employs a non location-specific data structure that assigns resilience categories to individual households. User-defined input variables for the amount of food-growing space required per person, and the maximum travel distance allowed, mean that different scenarios can be created. Two case studies of Christchurch and Stockholm are used to demonstrate how different datasets can be incorporated to give insight into the levels of resilience to food insecurity. Examples of potential sources of error caused by the variations in input dataset quality have been uncovered in the case studies, and possible strategies for dealing with these sources of error are discussed. Results of this study showed that greater maximum travel distances play a key role in accessibility of food in the urban environment, and that both cities are reliant on food retailers to supply food to the urban population, even when potential food growing space is taken into account. City planners or decision-makers can use the methodology developed in this thesis to make decisions about where potential growing space needs to be protected or allocated. They can also use it to model the potential effects of different scenarios, such as the addition of new subdivisions or changes in land use for public land.

This study attempts to find a correlation between commuting modes in Washington DC and characteristics of the city and the people that they serve. It investigates why some census tracts have experienced increases in the commuting share of alternative transportation, such as public transit, walking, and bicycling, while others haven't. Findings demonstrate that demographic variables such as percent Hispanic and foreign born were the strongest predictors of change in commute mode share followed by distance to train station. Land use variables demonstrated weak correlations with variations in mode share due most likely to a lack of density gradient within the study area. The creation of variables to determine land use mix by census tract posed technical challenges as well. Recommendations include policy addressing rising demand for more diverse transportation systems be implemented and further research be conducted on creating more accurate land use variables to include in the model.

The rapid urbanization of populations from rural areas to cities calls for more sustainable focused urban planning to combat the negative effects of urban sprawl. The United Nations’ Agenda 2030 includes the 17 Sustainable Development Goals (SDGs) and 169 targets that aim to unite both developed and developing countries in transforming humanity and the planet for a more sustainable future. One of these goals is SDG 11, making cities and human settlements inclusive, safe, resilient and sustainable. A large part in achieving the targets of SDG 11 is measuring the current access urban residents have to things such as public green-blue spaces as well as public transportation. This thesis will aim to study Stockholm’s achievement of SDG 11 sub-targets 11.2 and 11.7 of Agenda 2030. In order to meet this aim, the following objectives will be pursued. The first objective is to study the degree to which Stockholm County currently has universal access to green-blue areas and public transportation by conducting a GIS-based analysis. The second objective is to improve our understanding of the socio-economic status of residents who have and do not have accessibility to green-blue areas and public transportation by statistically analyzing correlations between environmental and socio-economic indicators. The methodology included qualitative methodologies such as a literature review, interviews and collaborative focus group meetings with Södertörnsanalysen as well as quantitative methodologies such as spatial analysis and statistical analysis. The results show that while Stockholm has impressively high accessibility for its residents, it has yet to meet Agenda 2030 SDG 11targets 11.2 and 11.7 because the accessibility was not universal. The results also found that people with lower income, people who own their flats/homes and people with children have higher accessibility to green areas. It was also shown that people with higher income, people who rent their flats/homes and have no children have higher access to public transportation.This result can be expected as the bulk of people with higher incomes are living in the innercity where they have high access to urban services and rail stops, but not necessarily green areas. It is important to state that at 300 m from residencies, both access to green areas and access to public transportation is almost 100%. At 500 m from residencies, access to blueareas is close to 35 %, which is not almost complete, but still a high percentage since access to blue areas is a bit of a luxury. This thesis ultimately demonstrates the importance of understanding environmental and socio-economic indicators in urban planning especially if the goals of Agenda 2030 are to be met. This thesis also took steps towards building a methodology for quantifying accessibility and it is recognized that further studies can be conducted to further contribute to sustainable urban planning and development.
Den snabba urbaniseringen där människor flyttar från landsbygden till städer kräver en mer hållbar stadsplanering för att bekämpa de negativa effekterna av stadsutbredningen. FN:sAgenda 2030 innehåller 17 mål för hållbar utveckling (Sustainable Development Goals, SDG) och 169 delmål som syftar till att förena både utvecklade och utvecklingsländer i att omvandla mänskligheten och planeten för en mer hållbar framtid. Ett av dessa mål är SDG 11, vilket ska göra städer och mänskliga bosättningar inkluderande, säkra, resilient och hållbara. En stor del i att uppnå målen med SDG 11 handlar om den nuvarande tillgången stadsborna har till bland annat offentliga gröna och blå ytor samt kollektivtrafik. Arbetet syftar till att studera Stockholms måluppfyllelse när det gäller SDG 11 delmål 11.2 och 11.7 i Agenda 2030. Föratt mäta uppfyllelsen av dessa delmål har studien följande mål. Det första målet är att studera i vilken grad Stockholms län idag har allmän tillgång till gröna och blå områden och kollektivtrafik genom att genomföra en GIS-baserad analys. Det andra målet är att förbättra vår förståelse för den socioekonomiska statusen hos boende som har respektive inte har tillgång till gröna och blå områden och kollektivtrafik genom att statistiskt analysera sambandet mellan miljöinriktade och socioekonomiska indikatorer. Metoden innefattade kvalitativa metoder som litteraturöversikt, intervjuer och samverkande fokusgruppsmöten med Södertörnsanalysen samt kvantitativa metoder som rumslig analys och statistisk analys. Resultaten visar att medan Stockholm har imponerande hög tillgänglighet för sina invånare, har det ännu inte uppfyllt Agenda 2030 SDG 11 mål 11.2 och 11.7 eftersom det visades att tillgängligheten inte var universell. Resultaten visar också att personer med lägre inkomst, personer som äger sina lägenheter/hem och personer med barn har högre tillgänglighet till grönområden. Det visades också att personer med högre inkomst, personer som hyr sina lägenheter/hem och inte har barn har högre tillgång till kollektivtrafik. Detta resultat kan förväntas eftersom en stor andel personer med högre inkomster bor i innerstaden där de har hög tillgång till kollektivtrafik och urban service, men inte nödvändigtvis grönområden. På ett avstånd av 300 m från bostäder, är både tillgång till grönområden och tillgång tillkollektivtrafik nästan 100 %. Vid ett avstånd av 500 m från bostäder är tillgången till blåområden nära 35 % vilket är långt ifrån alla, men fortfarande en hög andel eftersom tillgång till vattenområden och stränder kan ses som lite av en lyx. Denna studie visar dessutom vikten av att förstå miljö- och socioekonomiska indikatorer i stadsplaneringen, särskilt om målen i Agenda 2030 ska uppfyllas. Denna studie tog också initiativ till att bygga en metod för att kvantifiera tillgängligheten, medan vidare studier behöver genomföras för att ytterligare bidra till stadsplanerings- och utvecklingssektorn.

This research intends to develop a more comprehensive and accurate GIS-based Spatial Equity Assessment Framework. The purpose is to provide guidance for measuring potential accessibility integrating size and assessing spatial equity integrating quality for social groups at the household level on the city scale. The research reviews the existing studies in planning and health-related fields on disaggregation techniques, potential accessibility and potential access measurement and spatial equity assessment. As the most accurate place access measurement method, the Population Weighted Centroid (PWC) technique suffers from aggregation errors, a cadastral and address-based population weighting technique, the Household Space Weighting (HSW) technique is developed to measure population access. The HSW technique is formally tested in a case study of General Practitioner (GP) surgeries in Newcastle upon Tyne, UK. The findings suggest that the PWC technique produces inaccurate population estimations for 267 out of 910 output areas in the city. When applying the two techniques to measure potential accessibility for social groups, taking into account the overlay of service areas on the city scale, the measurement error for the PWC technique is 9-11%, depending on the social group considered. The relative difference in the percentage of social groups with potential access applying the two techniques is 18-22%. This suggests that if service planners or policy makers want to measure potential access to services for social groups in their cities, it would be useful to apply a more accurate population weighting technique, or to at least be aware of the implications of applying the PWC technique. The research also demonstrates the necessity of incorporating demand apart from equality and need and integrating quality in addition to size into spatial equity assessment framework. Thus, the GIS-based Spatial Equity Assessment Framework that is developed in this research is more comprehensive and accurate than the existing studies. The research summarizes how to apply the assessment framework to provide policy recommendations for cities on the city scale. The assessment framework has potential to extend from measuring potential access and assessing spatial equity of healthcare services to other services and from measuring potential access to realized access.

碩士
國立交通大學
交通運輸研究所
100
From 2007, Taiwan High Speed Railway (THSR) has been run for several years. THSR has taken a huge impact on the whole transportation market because it is more convenient and faster than the other inter-city transportation modes. From the literature review, we could know that most of the studies on high speed railway were the impacts on other transportation modes and the management policies on THSR, and seldom look into the measurement and change of the traffic accessibility. Therefore the goal of this study focuses to discuss the impact on each region from THSR. Based on literature review, this study proposed a moderate traffic accessibility index with gravity model and using the Employed Residence and the travel time to be the valuables, and the trips and population of each district to be the rating of travel time of the inter-city and intra-city . From social-economic development model we could know that traffic accessibility is related to population and employment in industry and commerce. So from the covariance to find out the moderate transportation index first. Secondly, used nonparametric method to test the addition of transportation accessibility after high-speed railway running. And, used cluster analysis to group the district by the existing transportation modes in each city to find out what is the key factor to different transportation accessibility besides high-speed railway. Finally, use the population, Employment Population, land use and traffic accessibility to establish the relative model to discuss the relationship between the traffic accessibility and social economic variables. The result shows that the most high accessibility is in south of Taipei and then north of Taipei, Kaohsiung city, Taichung city. However these cities are the center of the each region. Moreover the whole of accessibility gain is over than 28%, and some satellite counties are in better accessibility gain. Like Miaoli County, Nantou County, Changhua County, the accessibility gains of these countries are more than 40%. But the relative accessibility shows that the largest accessibility is south of Taipei (0.0997) and the smallest is Taitung County (0.0113), in other words, it means the difference of accessibility in each district is huge. Besides, according the relative model, the promotion of traffic accessibility in the past year will take the population in.

Despite the close proximity to downtown, East Austin is one of the more underprivileged and under-developed communities in the city of Austin, Texas. A lack of access exacerbates the lack of resources of the poor. It is essential to identify the current accessibility of urban facilities for East Austin’s residents in order to understand how the location of key support services serves to maintain East Austin’s underprivileged and under-developed status. The objectives of this study are 1) to evaluate the accessibility of residents in East Austin neighborhoods to urban facilities using spatial data analysis in geographical information systems (GIS), 2) to compare accessibility in East Austin with other Austin communities, including West Austin and North Austin, and, finally, this study will allow me to measure whether the more underprivileged populations of East Austin do indeed have equal access to urban facilities and, if not, to identify which neighborhoods in East Austin offer the best access. In shortly, I can see that many public owned facilities, such as Sports and Recreational, Educational, Health, and some of Community Service facilities are relatively dispersed in poor neighborhoods in the City of Austin. It should be noted that public authorities have made deliberate choices to distribute facilities in poorer neighborhoods.
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碩士
國立成功大學
國際經營管理研究所碩士班
100
Small and medium enterprises (SMEs) considered as a key force for growth of local economies to generate employment, to create level of new business formation, and to help diversify economic activity by innovation. Therefore, countries use SME as a poverty alleviation tool to reduce poverty. The purpose of this study is to employ the logit model to investigate the factors affecting bank loan accessibility for SMEs in Mongolia. Survey questionnaire was used to define the factors that are mostly affecting and the sample is focusing on more micro and small businesses. The study defines what kind of characterized SMEs tend to apply for bank loan and determines what factors affect loan acceptance for those SMEs have applied for bank loan.

South Africa is experiencing a financial skills shortage with a severe shortage of accountants and chartered accountants in particular. The aim of this study was to measure accessibility of public higher education in South Africa, in general and specifically relating to accountancy programmes with special emphasis on chartered accountancy programmes in South Africa, by making use of selected accessibility indicators. Although some of these indicators have been used to measure accessibility of higher education in general both locally and internationally, they are not often used to measure accessibility of a programme for a particular profession such as accountancy or chartered accountancy. This study aimed to fill this gap by measuring the selected accessibility indicators and providing subsequent rankings of the four public universities selected for this study. The results can be used by institutions that offer accountancy and chartered accountancy programmes as well as the South African Institute of Chartered Accountants, as the profession’s Education and Training Quality Assurance body, to evaluate the accessibility of accountancy as well as chartered accountancy programmes.
Financial Accounting
M. Compt. (Applied Accountancy)