Accessibility modelling: predicting the impact of planned transport infrastructure on accessibility patterns in Edinburgh,UK

The achievement of good spatial accessibility and equity in the distribution of urban services is one of the supreme goals for urban planners. With Scottish Government backing, the City of Edinburgh Council (CEC) has started to construct a tram network to cater for the future needs of Scotland’s capital city by providing an integrated transport solution using trams and buses. Spatial Network Analysis of Public Transport Accessibility (SNAPTA) which is a GIS-based accessibility model has been developed to measure the accessibility by public transport to different urban services and activities. The model responds to several limitations in other existing accessibility models in planning practice. It offers an alternative and practical tool to help planners and decision makers in examining the strengths and weaknesses of land use – transport integration. SNAPTA has been applied to a pilot study in Edinburgh city to identify the contribution of the infrastructure improvements of the tram system and Edinburgh South Suburban Railway (ESSR) to improved accessibility by public transport to six types of activity opportunities. This paper outlines the concept and methodology of the SNAPTA model, and presents the findings related to this pilot study with a focus on changes in potential accessibility to jobs between four different public transport network scenarios. The accessibility values so obtained help to identify the gaps in the coverage of the public transport network and the efficiency in the spatial distribution of urban services and activities. The findings focus on whether the planned transport infrastructures for Edinburgh will lead to better accessibility and reduced inequity (in terms of accessibility) across the city.     

Evaluating the European added value of TEN-T projects: a methodological proposal based on spatial spillovers, accessibility and GIS

This paper develops a methodology for calculating the European value added value (EVA) generated by transport infrastructure projects. This approach is particularly useful for evaluating projects in the framework of Trans-European Transport Networks (TEN-T), although it may also be used in trans-national projects in other geographical areas. The methodology is based on the appraisal of spatial spillovers generated by trans-national projects by using accessibility indicators (access to markets) and Geographical Information Systems (GIS). Projects are split into sections and spillover effects of each section are then computed. The sections that produce a high proportion of spillovers in relation to internal benefits generate a high EVA. Additionally, indicators are obtained of the effects of each section in terms of spatial concentration on the different countries affected, efficiency (general improvement in accessibility) and territorial cohesion (reduction in accessibility disparities between regions). The validity of this approach is verified by applying it to TEN-T priority project 25. This methodology does not seek to replace existing project appraisal methodologies (particularly the cost-benefit analysis); rather it provides complementary data for decision-making. Sections which are scarcely profitable from the cost-benefit analysis perspective but which have high European value added should receive more European funding than more profitable sections of markedly national interest.     

Accessibility impact of the present and future high-speed rail network: A case study of Jiangsu Province,China

The large-scale implementation of a high-speed rail (HSR) network is often considered to have a significant effect on the spatial distribution of accessibility. In China, the development of HSR network has progressed rapidly since the first line commenced operation in 2008. As an important component of this network, Jiangsu province proposed an ambitious HSR construction program which planned to cover over 95% of its counties by 2030. Reduced travel time for passengers is one of the most important effects of HSR, and therefore this study aims to analyze the accessibility impact of the evolving HSR network in Jiangsu province from 2010–2030. A layered cost distance method, based on a door-to-door approach, is proposed to evaluate the present and future accessibility at a more detailed geographical level. The results demonstrate that, with the gradual development of the HSR network, accessibility levels across the province will be improved by about 9.6%, and the distribution of the gains will be uneven since the most significant improvements will occur in the more peripheral areas. The inequality in regional accessibility will decrease by an average of 25.7%, which will produce a more homogeneous accessibility landscape. In addition, several policy measures are suggested in order to further enhance the competitiveness of the HSR network in the transport market at a regional level. This extended period of exploratory and detailed analysis is expected to facilitate proactive public policy decisions related to improving the transport network.     

Measuring the long-distance accessibility of Italian cities

Long-distance accessibility is a crucial element for economic development and for territorial cohesion. To be revealing, however, a measure of accessibility must not only consider the distance or travel time of a single mode, but should include the fares, the frequency and the interchanges of all available modes.The paper aims to address whether and where there is an accessibility problem between Italian regions, through a comprehensive measure of accessibility covering the entire Italian territory. The measure used in the paper is potential accessibility, with an exponential decay impedance function. Different from similar studies, this one gives a more in-depth definition of impedance parameters due to the availability of a transport model that includes the entire Italian long-distance supply (roads, coaches, long-distance rail services, air services, and ferries). The opportunities at destination are proxied by population, and private and public sector employees.The main outputs are detailed maps of accessibility that are significantly more realistic than using simple infrastructure indicators or single-mode measures. In addition, some policy conclusions are drawn in terms of past and future investment policies.     

Inter-regional air transport accessibility and macro-economic performance in Japan

Although there have been various studies on macro-economic effect of public investment, not much attention has been paid to the impact of actual accessibility realized by transport industry and infrastructure. In this paper, we performed a cross-sectional analysis of 47 prefectures in Japan between 1995 and 2000 by Cobb–Douglas production function and growth regression approach. The results explain why deregulation and infrastructure development in air transport during 1990s manifest mixed results of inter-regional accessibility and per-capita GDP growth for core and peripheral areas in Japan.     

Spatio-temporal evolution of cities and regional economic development in Nepal: Does transport infrastructure matter?

The literature on the New Economic Geography (NEG) suggests that transport cost is a major driving factor for the emergence of core–periphery patterns within a country. However, very few studies have tested this theoretical explanation in the context of transport infrastructure networks in developing countries. This paper takes a closer look at Nepal and tests four expectations that are drawn from the NEG, which highlight different aspects of the formation of core–periphery dynamic as determined by infrastructure quality. The expectations are tested by relating spatial-temporal patterns of road development to the growth and distribution of cities and examining the transport infrastructure contribution to shaping the patterns of regional economic development. We used intercity travel time estimates, based on the design speed of roads, length of sections and pavement type (from 1961 onwards in 10-year segments) as an indicator for the quality of infrastructure (transportation cost). Next, we computed hubness and accessibility indices of cities, defined by means of a gravity model and as a function of transportation cost, to undertake a cross-city comparison. We applied GIS mapping, multiple regression and mediation analysis techniques to relate these transport and accessibility characteristics to spatio-temporal patterns in city size and GDP per capita. Our study broadly confirms the core expectation derived from the NEG that transport improvements facilitate urbanization and that higher urbanization leads to higher regional GDP per capita. Two independent effects were identified in qualification of these overall patterns – the impact of market potential on city primacy and the impact of highly localized, immobile resources on GDP.     

Electrification of a city bus network—An optimization model for cost-effective placing of charging infrastructure and battery sizing of fast-charging electric bus systems

The deployment of battery-powered electric bus systems within the public transportation sector plays an important role in increasing energy efficiency and abating emissions. Rising attention is given to bus systems using fast charging technology. This concept requires a comprehensive infrastructure to equip bus routes with charging stations. The combination of charging infrastructure and bus batteries needs a reliable energy supply to maintain a stable bus operation even under demanding conditions. An efficient layout of the charging infrastructure and an appropriate dimensioning of battery capacity are crucial to minimize the total cost of ownership and to enable an energetically feasible bus operation. In this work, the central issue of jointly optimizing the charging infrastructure and battery capacity is described by a capacitated set covering problem. A mixed-integer linear optimization model is developed to determine the minimum number and location of required charging stations for a bus network as well as the adequate battery capacity for each bus line. The bus energy consumption for each route segment is determined based on individual route, bus type, traffic, and other information. Different scenarios are examined in order to assess the influence of charging power, climate, and changing operating conditions. The findings reveal significant differences in terms of required infrastructure. Moreover, the results highlight a trade-off between battery capacity and charging infrastructure under different operational and infrastructure conditions. This paper addresses upcoming challenges for transport authorities during the electrification process of the bus fleets and sharpens the focus on infrastructural issues related to the fast charging concept.     

Analysing transport corridor policies: An integrative approach to spatial and social disparities in India

Although strategies to create transport corridor are prevalent in the global South, there is a lack of empirical research to evaluate these initiatives, in particular whether they have realised their general goal of reducing regional disparities. The current paper describes a multi-method approach involving spatial and non-spatial analysis to investigate spatial disparity along a proposed corridor and examine its integration within the existing settlement structure. The analytical framework is tested on India’s Delhi-Mumbai Industrial Corridor. A rationale is developed to enable a critical view of corridor policies as strategies for development in the global South.One important finding regarding policies on transport corridors is the risk that future growth will remain concentrated in districts directly linked to a proposed corridor, leaving peripheral areas marginalised. An integrative analysis of current spatial and social disparities in India shows growth to be high in areas with good accessibility between urban and rural areas. Specifically, growth in rural areas is fostered by the availability of good road network, and polytechnic and vocational institutions, whereas in urban areas, growth is positively associated with the provision of secondary schools. In order to prevent or even reduce disparities, this research recommends that spatial strategies be developed with mechanisms to enable their implementation by lower tiers of governments, that spatial plans and infrastructure outlays be reformed to improve accessibility between proposed corridors and peripheral areas, and that accessibility indicators be included in the design and implementation of transport development policies.     

Territorial cohesion impacts of high-speed rail under different zoning systems

Large-scale transport infrastructure projects such as high-speed rail (HSR) produce significant effects on the spatial distribution of accessibility. These effects, commonly known as territorial cohesion effects, are receiving increasing attention in the research literature. However, there is little empirical research into the sensitivity of these cohesion results to methodological issues such as the definition of the limits of the study area or the zoning system. In a previous paper (Ortega et al., 2012), we investigated the influence of scale issues, comparing the cohesion results obtained at four different planning levels. This paper makes an additional contribution to our research with the investigation of the influence of zoning issues. We analyze the extent to which changes in the size of the units of analysis influence the measurement of spatial inequalities.The methodology is tested by application to the Galician (north-western) HSR corridor, with a length of nearly 670 km, included in the Spanish PEIT (Strategic Transport and Infrastructure Plan) 2005–2020. We calculated the accessibility indicators for the Galician HSR corridor and assessed their corresponding territorial distribution. We used five alternative zoning systems depending on the method of data representation used (vector or raster), and the level of detail (cartographic accuracy or cell size). Our results suggest that the choice between a vector-based and raster-based system has important implications. The vector system produces a higher mean accessibility value and a more polarized accessibility distribution than raster systems. The increased pixel size of raster-based systems tends to give rise to higher mean accessibility values and a more balanced accessibility distribution. Our findings strongly encourage spatial analysts to acknowledge that the results of their analyses may vary widely according to the definition of the units of analysis.     

Accessibility measurements in São Paulo,Rio de Janeiro,Curitiba and Recife,Brazil

Increasing attention is given to public transport services in cities of the Global South as a tool to enhance social inclusion and support economic development. Against this background, developing and evaluating indicators that quantify the distribution of public transport services from a social equity perspective is essential. The aim of the study is, therefore, to assess the equity of public transport services in four metropolitan regions in Brazil (São Paulo, Rio de Janeiro, Curitiba and Recife) with two commonly used indicators of public transport provision. The first indicator measures proximity to rapid transit infrastructure (bus rapid transit, light rail and heavy rail stops with high frequency throughout the day), and the second measures accessibility to jobs by public transport. While simple indicators of proximity to public transport stops are most commonly used given their ease of operationalization and communication, accessibility to job indicators are more representative of the benefits provided to individuals by the public transport network. Combining these two indicators in one study provides a quantitative assessment of the socio-spatial distribution of public transport services in four large metropolitan areas in Brazil and the results demonstrate that lower-income households are disadvantaged in terms of public transport services in all four metropolitan areas. Furthermore, the results highlight the importance of quantifying accessibility by public transport, in addition to proximity to rapid transit, and thereby sheds light on the importance of developing openly available public transport schedules and geographic data. This study is of relevance to planners and researchers wishing to measure and evaluate public transport equity in the Global South.     

Future accessibility impacts of transport policy scenarios: Equity and sensitivity to travel time thresholds for Bus Rapid Transit expansion in Rio de Janeiro

The accessibility impacts of transport projects ex-post implementation are generally evaluated using cumulative opportunity measures based on a single travel time threshold. Fewer studies have explored how accessibility appraisal of transport plans can be used to evaluate policy scenarios and their impacts for different social groups or examined whether the results of project appraisals are sensitive to the time threshold of choice. This paper analyzes how different scenarios of full and partial implementation of the TransBrasil BRT project in Rio de Janeiro (Brazil) will likely impact the number of jobs accessible to the population of different income levels. The analysis is conducted under various travel time thresholds of 30, 60, 90 and 120 min to test whether the results are sensitive to the boundary effect of the modifiable temporal unit problem (MTUP). Compared to a partial operation scenario, the full implementation of TransBrasil that extends this corridor into the city center would lead to higher accessibility gains due to network effects of connecting this BRT to other transport modes. Nonetheless, the size of the accessibility impacts of the proposed BRT as well as its distribution across income classes would significantly change depending on the time threshold chosen for the accessibility analysis. Considering cut-off times of 30 or 60 min, both scenarios of TransBrasil would lead to higher accessibility impacts in general and particularly for low-income groups, moving Rio towards a more equitable transportation system. However, under longer thresholds of 90 and 120 min, an evaluation of this project would find much smaller accessibility gains more evenly distributed by income levels. The paper highlights how time threshold choice in cumulative opportunity measures can have important but overlooked implications for policy evaluation and it calls for further research on the MTUP in future transport and mobility studies.     

The European high-speed train network: Predicted effects on accessibility patterns

The principal aim of this paper is to evaluate the impact of the future European high-speed train network on accessibility, by reducing time distance between places and modifying their relative location. We compare the current situation with that foreseen for the year 2010, according to the Outline Plan of the European High-Speed Train Network, in order to analyse which areas will most benefit from construction and improvement of the infrastructure. It is hypothesized that the high-speed train will certainly bring the peripheral regions closer to the central ones, but will also increase imbalances between the main cities and their hinterlands. A weighted average distance indicator is applied for this purpose. This measure identifies the spatial distribution of accessibility in the area of study, emphasizing the infrastructure effects, and locates accessibility changes at the European level. A Geographic Information System (GIS) has been used to carry out this study.     

From colonization to national territories in continental West Africa: the historical geography of a transport infrastructure network

This paper argues that in order to study the geohistory of a transport infrastructure network it is necessary to identify the link between networks and territorial scales during a given period. It focuses on the creation of road and rail networks in French West Africa during the colonial period and in the land-locked States during the national period, which involves post-independence development policies. The network is perceived in this paper as the manifestation of the political will to facilitate traffic within a delimited space. Within the colonial and then the national periods roads and railways were thus constructed as part of a process that can be interpreted as the outcome of a compromise between a territorial project and the capacity to implement it. This geohistorical study thus allows us to identify, with reference to the link between borders and networks, the successive geographical linkages (railway and port combinations with their subsequent branches, national roads, economic roads, external connections) which have been applied in the delimited spaces in question. This exercise has concentrated particularly on continental West Africa.     

Potential performance of urban land use and transport strategies in reducing greenhouse gas emissions: Khon Kaen case study,Thailand

ABSTRACT

Transport activities are a key contributor to greenhouse gas (GHG) emissions, global warming, and climate change. In Thailand, private cars are the second largest generator (after trucks) of GHG emissions from the transport sector. This article presents an analysis and evaluation of the implementation of land use and transport measures for reducing GHG emissions in the road network of the Khon Kaen University (KKU) area in Khon Kaen, Thailand. This research applied a bottom-up method to estimate the baseline GHG emissions for several scenarios by adopting the Clean Development Mechanism 2 (CDM2) and Pollution Control Department (PCD) methods over a 20-year planning horizon. The cleaner technology strategy clearly showed the greatest performance in reducing the GHG emission, followed by land use planning and restriction of private vehicle usage. The public transit improvement strategy illustrated the least GHG emissions reduction. Integrated scenarios clearly illustrated larger potential benefits, more effective than the individual scenarios. For both individual and integrated scenarios, the potential performances of the GHG emissions reduction estimated by the PCD method were greater than those assessed by the CDM2 method.     

Planning for low carbon mobility: Impacts of transport interventions and location on carbon-based accessibility

Accessibility has been conceptualized and applied in different ways, depending on the underlying political objectives. In the context of climate change and ambitious emission reduction targets, environmental concerns have risen high on the political agenda. Existing methods for assessing transport-related environmental impacts typically depend on realized or modeled travel behavior. Many of them do not entail a spatial dimension, ignore the importance of the land use component, lack scenario building capabilities or have limited communication value. Consequently, accessibility analysis and planning could make a valuable contribution towards a low carbon transition, but needs to attune to the specific objective of reducing transport-related greenhouse gas emissions. This paper introduces a novel conceptualization of location-based accessibility, where CO₂ emissions are used as a travel cost in place of time or monetary costs. By identifying and assessing options for interventions in the land use and transport system, carbon-based accessibility instruments might serve a number of potential decision-making purposes related to low carbon mobility planning. Carbon-based accessibility of a business park in the Munich region is analyzed in multiple scenarios to demonstrate the application potential of the method. The experiential application focuses on the effects of changes in vehicle efficiency and occupancy rates of both car and transit, but also compares the resulting carbon-based accessibility levels to alternative sites with the transport system unchanged. Applying carbon-based accessibility instruments to real-world planning issues could enhance strategic decision-making processes in the context of climate change mitigation.     

Accessibility gains and road transport infrastructure in Spain: A productivity approach based on the Malmquist index

Accessibility, the relative access to markets, is a strategic concept in all economic models with a spatial dimension and its prominence has been acknowledged in many economic research fields and policy debates. This paper is based on the assumption that infrastructure drives economic accessibility and, therefore, we can assimilate a production function approach where the road network constitutes a set of inputs yielding access to markets as output. Methodologically, we originally measure the infrastructure inputs accounting for the real used network and calculate a series of new final and intermediate demand gravity-based and locational indicators, which capture a wide range of economic transactions and represent different concepts of economic accessibility outputs. The value added of this paper is translating a non-parametric frontier approach (DEA) to a dynamic scope (Malmquist indices) by connecting the regional accessibility to the productivity of the road infrastructure inputs associated with each region. Results during 1995–2005 show a low relative accessibility of the Spanish NUTS-3 regions, although improvements have been greater over the last five years. Finally, we observe a U-inverted relationship between the accessibility gains during these years and the geographical localization.     

The impact of the great recession on Irish air travel: An intermodal accessibility analysis

This paper quantifies the changes in accessibility at small area scale arising from the combined effects of dramatic air traffic declines and a greatly expanded motorway network in Ireland during the period of the great recession. The subsequent policy decisions by government are assessed in light of the intermodal accessibility changes identified. The Irish Government engaged in an extensive motorway construction programme throughout the 2000s, greatly increasing the overall length of the inter-urban motorway network. The essential air transport services programme put in place in the 1990s to guarantee a minimum level of air access to disadvantaged regions was significantly reduced at the end of the 2008–2011 period, with only two of the six regional airports continuing to have any form of subsidised public service obligation for the period 2011–2014. In this study, small area datasets are used to measure the net impact of these changes on air transport accessibility in Ireland and the potential spatial inequalities that arise as a result of these changes. An inter-modal accessibility approach is used where the physical characteristics of the road transport network to airports and the network structure characteristics of the air transport system are taken into account to evaluate the levels of air transport accessibility at the small-area district level. Results from the analysis show that the improved surface access to the larger Irish airports (Dublin and Belfast) has enhanced the range of European and global locations directly accessible by air for many communities in Ireland. The net effect of these changes has been to concentrate air traffic at the largest Irish airports.     

Tourism,climate change and the mass media: the representation of the issue in Spain

This paper sets out to analyse the information dedicated to climate change and tourism in the Spanish press in the Mediterranean region of the peninsula during the period 1990–2010. Specifically, it seeks to determine the quantitative evolution of media coverage of climate change and tourism and the importance given to this subject. Adequate media attention in both quantitative and qualitative terms could greatly influence public concern and contribute to the social mobilization that will be needed to negotiate/resist the phenomenon in a geographical area in which tourism is a major economic and territorial driver and which is particularly vulnerable to climate change. To construct the corpus, we undertook a systematic analysis of newspaper coverage of tourism and climate change in the media selected; and we carried out content analysis of the 1014 units identified. The results indicate that the coverage is outstanding in quantitative terms. However, the importance given to the subject is quite marginal.     

Impacts on accessibility of China’s present and future HSR network

Although the construction of China’s high-speed rail (HSR) network only started in 2003, the network is already the largest in the world. This paper analyses the impact of the evolving HSR network on the accessibility by HSR and conventional ground transport of 333 prefecture-level cities and 4 municipalities. This paper employs three indicators of accessibility, and analyses three Scenarios. It shows that the HSR network will bring about substantial improvement in accessibility, and lead to national time–space convergence, but will also increase the inequality of nodal accessibility between eastern, central, and western regions, between cities with different sizes of population (excluding the case of the daily accessibility indicator) and between cities that differ in the shortest distance to HSR stations. The HSR network enlarges internal disparities in each of the regions and the five types of cities. The internal inequality of nodal accessibility in all three Scenarios generally increases from the eastern region via the central region to the western region, as well as from very large cities to small cities, varying inversely with the level of economic development and population size. Spatially, accessibility increases generally conform to the distance decay rule but with minor fluctuations. The 50 cities with the largest increases in accessibility are mostly located 50 km or less away from HSR stations and have populations of over 3 million, with the smaller ones located along HSR lines or around large cities such as Beijing, Shanghai, and Guangzhou. As time progresses, the planned HSR network will result in more balanced development, but regional disparities in accessibility will still be greater than before the construction of the HSR.     

Location quotient-based travel costs for determining accessibility changes

Accessibility is not a static feature because it is affected by a large number of factors, such as changes in transport infrastructure, the spatial distribution of human activities, and their interdependence. In this study, we examine the role of location quotient-based travel costs as the travel impedance function in accessibility measurement to better capture accessibility changes over time. The travel impedance function is one of the most widely studied aspects of accessibility. In most studies, travel impedance is determined by a negative exponential function in the travel cost assessment of the accessibility measure as a means to incorporate the distance decay effect. Here, we apply an accessibility index that uses location quotient-based travel costs and an accessibility measure with simple travel costs in order to test the proposed theory. The results of the two methods vary considerably. The location quotient method is discussed in detail, including its potential advantages for measuring accessibility changes. We argue that the location quotient-based travel cost is an appropriate method for determining the travel impedance function in accessibility measurements, especially for analyzing accessibility changes.