Identification of critical sections of the Spanish transport system due to climate scenarios

In recent years climate change has become a multidisciplinary research topic that addresses the challenges facing transport infrastructure planning, construction and operation. The study of the adaptation of transport systems to new environmental conditions is often based on the interrelated concepts of resilience, vulnerability and criticality. In this paper we assess the criticality of sections of Spain's inland transport network under the effects of changing climate scenarios obtained from a specific climate projection (using the time periods 2010–2020 and 2045–2055). The functionality of the transport system is characterised here in terms of territorial accessibility. The results identify and locate the most critical stretches of the Spanish transport network. In general terms, the most relevant sections in regard to accessibility will not be exposed to the greatest changes in climate variables. Up to 2.8% of the roads and 5.9% of the railways that contribute most significantly to the territorial accessibility of the transport system will undergo the greatest variations between climate scenarios. This paper contributes to this field of research by developing a screening tool that represents a valuable instrument for the infrastructure decision-making process at the strategic level. Action areas for proactive adaptation measures can be identified in order to reduce impacts and costs, while prioritising the maintenance or reconstruction of the most critical stretches in the case of a future climate event.     

The impacts of high-speed rail extensions on accessibility and spatial equity changes in South Korea from 2004 to 2018

The construction of South Korean High-Speed Rail (HSR) or Korea Train eXpress (KTX) has been evolving in phases since its first operation in 2004. This development raises concerns whether the benefits from the extended HSR network would again be limited to the initial HSR corridors and will deepen the inequalities in accessibility with the rising issue of uneven regional development of the country. This paper measures the accessibility of each stage of HSR network extension and evaluates its spatial distribution, variation, and changes using weighted averaged travel time and potential accessibility indicators. The results of this study find different accessibility impacts from each stage of HSR extension. Although travel-time reduction and increased attractions have been widened in more cities by each HSR extension, the spatial equity is degenerated by the extension in 2010/2011 as the improvement of accessibility has been concentrated in cities along the primary HSR corridor near the already-advantageous Seoul capital area. In contrast, the future HSR extension in 2018 will enhance equitable accessibility to the isolated regions such as the northeast and the southwest regions of the country. However, the relative degree of accessibility improvement will not be large enough for increasing the spatial equity of accessibility without more extended HSR networks between provinces.     

Spatial analysis of access to and accessibility surrounding train stations: a case study of accessibility for the elderly in Perth,Western Australia

Approximately one-fifth of Perth’s population is aged 60 or older. Projections suggest that this proportion will continue to increase as a result of the large number of children born after the World War II (1946–1964). Access to and accessibility around train stations for the aging population is and will become a more important issue as the elderly population continues to grow. The aim of the paper is to develop and apply a new measure of accessibility to train stations at a fine spatial scale, justified by the special circumstance of the elderly using a case study in Perth, Western Australia. Intercept surveys are used to collect data on factors affecting train station accessibility for patrons aged 60 years or older, at seven highly dispersed train stations. Overall accessibility is measured separately using a composite index based on three travel modes (walk-and-ride, park-and-ride and bus-and-ride). The results illustrate that key variables, such as distance from an origin to a station, walking or driving route directness, land-use diversity, service and facility quality, bus connection to train stations, all affect the accessibility to train stations for the elderly. This implies that improvements to these factors will improve accessibility for this population group.     

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.     

Impacts of high-speed rail on the inequality of intercity accessibility: A case study of Liaoning Province,China

The rapid development of Chinese high-speed rail (HSR) not only improves the convenience of daily transportation, but also promotes the regional economy of cities along the HSR lines. Accessibility improvement and spatial inequality reduction caused by HSR would play a positive role in transportation development projects appraisal and help achieve the regional coordinated development. Our purpose is to assess how much improvement of economic potential accessibility can each city get from the HSR based on the existing highway and HSR networks, as well as the changes in spatial disparity and accessibility distribution patterns. Taking Liaoning Province as a case, this paper studies the spatial pattern and inequality of accessibility in two intercity transportation scenarios using a gravity-based model. The sensitivity analysis of the parameter and the test of different mass indicators are also conducted. The results show that cities in the central areas have better accessibility than peripheral areas. Cities in the peripheral areas and near the HSR lines tend to benefit more from HSR. The inequality of accessibility decreases a lot in cities with HSR access but only has a minor reduction on a whole scale.     

Spatial and temporal heterogeneity of the impact of high-speed railway on urban economy: Empirical study of Chinese cities

The relationship between high-speed railway (HSR) construction and economic development has become a significant concern in recent decades. This study uses the spatiotemporal panel data of China's HSR construction and economic development from 2008 to 2018 as bases to discuss the spatial–temporal heterogeneity of the relationship between HSR and the urban economy. Firstly, this research measures the accessibility of different dimensions (i.e. location accessibility, potential accessibility and daily accessibility), and assesses the regional disparity of HSR accessibility and urban GDP using the Gini index. Secondly, the direct and indirect effects of HSR on economic development are analyzed from the global perspective by using the spatial Durbin model. Lastly, the geographically and temporally weighted regression model is applied to assess the spatial–temporal heterogeneity of the correlation between HSR and economic development from a local perspective. The conclusions are as follows. (1) The construction of HSR might reduce the regional disparity of daily accessibility, but expand the disparity of potential accessibility and location accessibility. (2) From a global perspective, HSR has a significant positive impact on urban economic development, but this impact was mainly produced by the spillover effect and not the direct effect. Specifically, the smaller the spatial–temporal distance between cities, the higher the level of regional integration and the better the economic development of cities. (3) The HSR impact on urban economic growth has a periodic feature. The stimulation of large-scale railway construction will expand the economic effect of HSR, although network improvement will gradually converge the corresponding impact. (4) From a local perspective, the HSR impact on economic development has significant spatial heterogeneity. Although HSR has a certain inhibitory effect on the economic development of Eastern China, it has a positive impact on the economic growth of the western region.     

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.     

Transportation security and the role of resilience: A foundation for operational metrics

This paper presents operational metrics to determine a passenger transportation system's resilience to terrorism. The metrics range from those specific to the number of trips to more holistic measures that include the contribution of these trips directly and indirectly to economic activity. These metrics can aid decision-makers in rendering more informed judgments about resource allocation and how to design a portfolio of security and recovery strategies.The paper also provides a framework for evaluating transportation risk, including the important role of perceptions in potentially amplifying these risks. It provides a range of strategies to promote resilience as well. Resilience of a transportation system is then quantified using the real-world case of the 2005 London subway and bus bombings. In terms of ordinary resilience, we find that 77.4 percent of total journey reductions on attacked modes were offset by increases in substitute modes for the 4 months following the attacks. We also estimate that 76.9 percent of total journey reductions on attacked modes were the result of a “fear factor,” as opposed to capacity reductions.The paper concludes with a set of proposed prospective resilience measures to evaluate the potential resilience of a transportation system. These metrics are based on the vulnerability, flexibility, and resource availability to cope with a terrorist attack or natural disaster.     

Transport infrastructure development and changing spatial accessibility in the Greater Pearl River Delta, China, 1990–2020

This paper analyses the accessibility implications of the development of expressways and inter-city railways in the Greater Pearl River Delta (GPRD) over the period 1990–2020. Average travel time was firstly reduced by expressway development; and it will be reduced further by the introduction of the inter-city rail system in 2011. The unevenness in regional accessibility remained relatively high during the initial stage of expressway development, but later expansion brought more balanced accessibility landscapes. The first stage (2010–2020) of inter-city railway development will raise the accessibility inequality. Its later effects, however, remain to be seen. Convenience in transport connections is associated with the spatial pattern of industrialization. In addition, accessibility improvement is tied to the direction of city-region development, as exemplified by Guangzhou’s choice of Nansha, the city’s outer port, as development focus.     

Measuring the vulnerability of public transport networks

In the last years, studies on the vulnerability of public transport networks attract a growing attention because of the repercussions that incidents can have on the day-to-day functioning of a city. The aim of this paper is to develop a methodology for measuring public transport network vulnerability taking the Madrid Metro system as an example. The consequences of a disruptions of riding times or the number of missed trips are analysed for each of the network links with a full scan approach implemented in GIS (Geographic Information Systems). Using real trips distribution, each link in the network is measured for criticality, from which the vulnerability of lines and stations can be calculated. The proposed methodology also makes it possible to analyse the role of circular lines in network vulnerability and to obtain a worst-case scenario for the successive disruption of links by simulating a targeted attack on the network. Results show the presence of critical links in the southern part of the network, where line density is low and ridership high. They also highlight the importance of the circular line as an element of network robustness.     

The role of transportation accessibility in regional economic resilience

Whereas the importance of transportation for economic growth is widely acknowledged, past studies on the resilience of regions to economic shocks have not given explicit attention to the role of transportation accessibility on building robust regional economies. This exploratory study examines the regional performance in six U.S. states during the last recession (2008–2009) and post-recession (2010–2014) and evaluates its association with the transportation infrastructure. To account for spatial dependence and interactions, a exploratory spatial data analysis (ESDA), a global spatial autoregressive model, and a local Geographically Weighted Regression (GWR) are employed. Results show that, after controlling for other key aspects of resilience, such as industrial diversity and human capital, the global relationships between rail density, access to intermodal services, and access to local and regional markets were positively associated with regional performance (measured as competitive effect) during the recession. Similarly, positive regional performance before the recession period was associated with positive performance during the recession. The local spatial analysis, however, shows that the associations between the explanatory variables and regional performance vary significantly across space. The analysis and results of this study can contribute to a better understanding of the complex interactions between economic resilience and transportation infrastructure, and guide the development of policies and practices designed to strengthen the ability of regions to be resilient to economic shocks.     

Extending public transit accessibility models to recognise transfer location

A longstanding issue for public transit agencies has been how to assess the performance of transit service including spatial service coverage to meet the transport needs of the community. The conventional approach quantifies accessibility using door-to-door travel time in such a way that accessibility declines as the travel time to the opportunity increases. A new approach to modelling transit accessibility is proposed by incorporating the potential effect of transfer location. It builds on the premise that transit users may have a preference for a transfer location best located relative to the trip origin and destination points. The model is tested in Brisbane's bus network which has a radial form, where inner-city suburbs have relatively higher accessibility than outer-city suburbs, if only travel time is counted. Incorporating the transfer location refines the accessibility modelling so that some outer-city suburbs located along the major bus corridors have a relatively higher accessibility level. The new model also suggests that inner-city suburbs do not necessarily have better accessibility. Suburbs close to the city centre may have shorter transit travel time to reach other suburbs, but they do not have a well-connected transit network to other suburbs through service transfers.     

铁路快速客运网对城市通达性的影响

通达性是度量交通网络结构的有效指标,也是评价区域(或城市)获取发展机会和控制市场能力的有效指标之一.阐述城市通达性的评价方法,以31个省会级中心城市为研究对象,分别从各城市的节点总空间距离、节点总时间距离,快速客运网的网络总空间距离、网络总时间距离,城市节点通达性系数以及中心城市的日可达性等方面,分析“十二五”铁路快速客运网建设对城市通达性的影响.     

Bridges across borders: A clustering approach to support EU regional policy

We present a methodology to analyse high resolution population and transport data in order to assess cross-border connectivity within the European Union. Transport infrastructure can strongly influence cross-border interactions as well as regional, urban or local development. The analysis is carried out using a policy perspective, with network efficiency as the main indicator of accessibility. The aim is to allow the quantification of the quality of cross-border road connections and the identification of areas where infrastructure improvements can lead to higher benefits. We propose a machine learning approach that combines cell level route assignment and k-means clustering at a fine −1 square km- population grid. The outputs cover all internal EU land borders and consist of sets of spatial clusters that meet user-defined policy criteria. The results can be used as input for investment decisions and can be easily combined with other policy support tools for tailored multi-criteria analysis.     

An assessment method for highway network vulnerability

This paper introduces a methodology to assess the level of vulnerability of road transport networks. A new technique based on fuzzy logic and exhaustive search optimisation is used to combine vulnerability attributes with different weights into a single vulnerability index for network links, which may be used to measure the impact of disruptive events. The network vulnerability index is then calculated using two different aggregations: an aggregated vulnerability index based on physical characteristics and an aggregated vulnerability index based on operational characteristics. The former uses link physical properties such as its length and number of lanes, whilst the latter reflects aspects of the network flow. The application of the methodology on a synthetic network (based on Delft city, Netherlands) demonstrates the ability of the technique to estimate variation in the level of vulnerability under different scenarios. The method also allows exploration of how variation in demand and supply impact on overall network vulnerability, providing a new tool for decision makers to understand the dynamic nature of vulnerability under various events. The method could also be used as an evaluation tool to gauge the impact of particular policies on the level of vulnerability for the highway network and highlight weaknesses in the network.     

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.     

A PTAL approach to measuring changes in bus service accessibility

Accessible transport systems are essential to ensure equal opportunities for all people in society. The need for information about transport disadvantage is now a key policy requirement and previous studies have highlighted the need for tools to assess the impact of interventions on the bus network and the accessibility of the system. Geographical Information System (GIS) and ACCMAP enable the analysis of transport disadvantage and accessibility. This paper provides an analysis of the Citybus Network in Northern Ireland and assesses the spatial impact of a hypothetical network change on populations residing within the Citybus network area.     

Determining intra-urban spatial accessibility disparities in multimodal public transport networks

Urban rail systems have been added to public transport systems, thereby changing distribution disparities in urban spatial accessibility. These disparities reflect both the ability of the public transport system to meet the needs of residents and the locational pros and cons of public service facilities. In this paper, integrated accessibility metrics are used to assess the disparities in Nanjing, Jiangsu Province, China. This is achieved by dividing the urban space into a multilevel grid that can be easily combined with grid-based population data to facilitate accessibility modeling, calculation, and evaluation. Additionally, an acquisition method for more accurate travel time data in the multimodal public transportation network was developed on the basis of an Internet mapping service. This provides a realistic, multimodal, door-to-door modeling approach that avoids the requirement of building complex traffic networks through Geographic Information System (GIS) software and simplifies road network modeling efforts. The results show that this modeling method can be used to reflect the accessibility disparities in the Nanjing urban space objectively and accurately.     

Decision Support for an Optimal Choice of Subsidised Routes in Air Transportation

The aim of the work presented here is to develop a mathematical model that can assist decision-makers in selecting the optimal network of subsidised routes in air transportation. Sweden is used as a case study. The results show that even if most of the Swedish population already has a good accessibility, the model can suggest new routes that can further improve accessibility without increasing the subsidisation cost. The closure of an airport reduces the available commercial routes, which would impair the accessibility to a given destination; a subsidised route would hence be required as a replacement. The ability of the model to consider several accessibility criteria makes it useful for managers at transportation authorities when making airport location decisions.     

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.