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1.
Methods for the road network design problem, typically, are based on optimization of the network efficiency measures (e.g. network-wide travel time) under a predefined budget. In these approaches, equity issues are not taken into account and, consequently, most of the road improvements are planned next to large cities. Thus, disparities between large and small cities increase, which does not conform to sustainable development objectives. In this paper, to overcome concerns associated with traditional methods, equity is incorporated into the interurban road network design problem. To this end, accessibility concepts are employed. However, unlike previous studies, instead of maximizing the total accessibility, a new definition is proposed for inaccessibility, and total inaccessibility is minimized throughout the network. Using this new definition not only is more compatible with the equity issue, but also helps to eliminate the nonlinearity of the problem. Average travel time to neighboring opportunities is utilized to propose this definition for inaccessibility, which captures the reality more effectively. With the aim of this definition, equity is incorporated into the road network design problem implicitly. This is another improvement over previous methods, where a new term in the objective function or a new constraint is added to include the equity. The proposed model is formulated as a mixed integer linear programming (MILP) problem, where the objective is to minimize the aggregate inaccessibility over all the population centers in the network. To illustrate the application of the model, the Northwest region of the United States is used as the case study. The respective exact solution of the example is found using a commercial solver (CPLEX). This new solution is also compared with the solutions from the traditional methods. 相似文献
2.
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. 相似文献
3.
Every car trip ends with a parking search and parking. However, current transportation research still lacks practical tools and methodologies to analyze parking needs and dynamics, which cannot be adequately performed at an aggregate level. This paper presents PARKFIT, a novel algorithm for estimating city parking patterns that is based on a spatially explicit high-resolution view of the inherently heterogeneous urban parking demand and supply. Using high-resolution data obtainable from most municipal GIS, we apply PARKFIT to evaluate the fit between overnight parking demand and parking capacity in the city of Bat Yam, both currently and within the framework of the Bat Yam 2030 transportation master plan. We then analyze PARKFIT’s capabilities and limitations, and supply PARKFIT as a free ArcGIS-based software. 相似文献
4.
This study proposes the assessment of equity in transit provision by using transit connectivity as a comprehensive impedance measure. Transit connectivity considers in-vehicle time, access/egress times, waiting time, service reliability, frequency, and ‘seamless’ transfers along multi-modal paths. In addition, transit connectivity weighs the impedance components according to their relative importance to travelers. The assessment of equity was performed for the multi-modal transit system in the Greater Copenhagen Area, renowned for its transit-oriented finger-plan. The assessment method used a GIS representation of the network (i.e., service lines, timetables, metro stations, train stations, and bus stops), and transit assignment results (i.e., level-of-service times, passenger flows). The assessment method proved effective in calculating location-based and potential-accessibility measures and Gini coefficients of inequality in the Greater Copenhagen Area. Results show that the transit-oriented development contributes to spatial equity with high connectivity in densely populated zones, vertical equity with comparable connectivity in high income and low income zones, inter-generational equity with good connectivity provision for students to higher-education and job opportunities. Also, results show that the north-west ‘finger’ is less equitable with lower connectivity for low population density and lower connectivity to higher-education opportunities regardless of the high number of students. 相似文献
5.
Paula C. Morrow James C. McElroy Kevin P. Scheibe 《Transportation Research Part E: Logistics and Transportation Review》2011,47(6):1210-1220
Survey results from 1381 employees working in a state department of transportation tested the idea that uncivil work environments bear undesirable consequences for job satisfaction and diminish the effectiveness of quality management practices. Results demonstrated that incivility does not have to be personally experienced to have deleterious effects, merely witnessed. Perceived workplace incivility was found to adversely affect job satisfaction and the effectiveness of quality programs aimed at teamwork, customer focus and continuous improvement, even after controlling for race, gender and prior experience of harassment. Managers are advised to broaden their consideration of incivility to include its effects on observers. 相似文献
6.
The role of spatial spillover associated with the infrastructure–economy relationship has received increasing attention in the literature. Surprisingly, in previous studies, the potential spatial spillover effect of transportation infrastructure on economic output in the U.S. agricultural sector has not been taken into account given the sector’s importance in the economy and dependence on transportation. The broader effects, including the direct effect and spatial spillover effect, of transportation infrastructure on agricultural output across 44 states in the United States from 1981 to 2004 are estimated in this study. A spatial Durbin panel data model that catches spatial dependence in both dependent and explanatory variables is used. The results suggest that road disbursement in a given state has positive direct effects on its own agricultural output. Also, the spillover effect of road infrastructure on agricultural output in neighboring states varies with respect to the spatial weight matrix used in the model. Moreover, our analysis shows that enhancement in road infrastructure in the states in the U.S. central region has a larger positive spillover effect on agricultural output when compared to coastal or border states. 相似文献
7.
The individual vehicle replacement problem typical for freight transportation companies is discussed in the paper. Two characteristic features of such problem are that transportation companies utilise vehicles with intensity decreasing with an age of vehicles and that managers of such companies first of all take into account economical criteria when planning vehicle replacements. The paper presents a single criterion, nonlinear, deterministic and discrete mathematical model of such a problem that minimises a total exploitation and ownership costs calculated per kilometre. The exact solution procedure is proposed here. The problem is solved as a real life case study. As a result, an average, economically optimal 5-year exploitation period of vehicles has been determined. 相似文献
8.
《Transport Policy》2008,15(2):113-126
This paper presents a framework for examining the ways in which technical aspects of the regional transportation planning process are changing in response to a broadening of goals and strategies, driven in part by an increased emphasis on public involvement. As an illustration of this framework, the long-range plans of four Metropolitan Planning Organizations (MPOs) in the US are analyzed with respect to goals, performance measures, and use of forecasts. These examples suggest that changes in the technical aspects of the process are lagging changes in planning goals. As a result, plans may implicitly emphasize congestion relief even if they put forth a much broader range of goals. This paper provides a basis for further analysis of the current evolution of transportation planning in the US. 相似文献
9.
The concept of Functional Urban Regions (FURs), also called Metropolitan Regions (MRs), is not simple. It is clear, though, that they are not simply a combination of adjacent municipalities or areas. Different methods can be used for their definition. However, especially in developing countries, the application of some methods is not possible, due to the unavailability of detailed data. Alternative approaches have been developed based on spatial analysis methods and using variables extracted from available data. The objective of this study is to compare the results of two spatial analysis methods exploring two variables: population density and an indicator of transport infrastructure supply. The first method regards Exploratory Spatial Data Analyses tools, which define uniform regions based on specific variables. The second method used the same variables and the spatial analysis technique available in the computer program SKATER – Spatial ‘K’luster Analysis by Tree Edge Removal. Assuming that those classifications of regions with similar characteristics can be used for identifying potential FURs, the results of all analyses were compared with one another and with the ‘official’ MR. A combined approach was also considered for comparison, but none of the results match the existing MR boundaries, what challenges the official definitions. 相似文献
10.
This paper has been written in response to the Viewpoint contribution by the author Button (2012) entitled: “Is there any economic justification for high-speed railways in the United States?”. In this article, the Spanish HSR high-speed rail network is used as an argument against certain HSR investments. Several of the data presented by the author are misleading and some of the information given in connection with Spain is incomplete. As the Journal of Transport Geography is widely read by policymakers and the scientific community, Button’s misrepresentation could cause serious damage. We therefore set out to clarify the data used by Kenneth Button and to explore some points in greater detail, although in no case eschewing criticism of Spain. Although excessive Spanish investment in public infrastructure over the last twenty years has probably had a negative impact on the real estate bubble, investments in HSR infrastructure in Spain have specifically been accompanied by two particular facts that need to be distinguished from other countries’ experience. These facts cannot be overlooked and will be discussed in this paper. They relate firstly to the total amount of European funds used in HSR construction and secondly to the technological and scientific innovations developed in Spain linked to the HSR market. 相似文献
11.
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. 相似文献
12.
The introduction of traffic management schemes has been one response of the National Parks to the problem of ever-increasing car-borne visitors and the consequent damage caused to the rural environment. By reviewing these schemes and by determining and explaining attitudes towards one particular traffic management experiment, the paper aims to deduce lessons for future policy. The analysis, based on two visitor surveys, suggests that the likelihood of success is improved when schemes are integrated, containing both ‘carrot’ and ‘stick’ elements. Since public perceptions are also found to be pivotal to its success, appropriate marketing of a scheme is vital. The paper concludes, however, that to achieve the fundamental objective of greater accessibility with less mobility, a more wide-ranging marketing effort is required intended to engender a sea change in attitude towards both the car and public transport. 相似文献
13.
Robert C. Leachman Payman Jula 《Transportation Research Part E: Logistics and Transportation Review》2011,47(6):992-1004
A queuing model is introduced for estimating container flow times through port terminals as a function of infrastructure, staffing, and import volume. The model is statistically calibrated on industry data. Flow-time estimates of the model are aggregated with estimates from models previously developed for rail networks to develop estimates of the total container flow times from West Coast ports to inland distribution centers. Integrated with a supply-chain optimization model, the queuing formulas are used to predict import flows by port and landside channel in scenarios of total import growth, varying all-water rates, and a higher import share for nation-wide importers. 相似文献
14.
We propose a multi-depot location-routing model considering network failure, multiple uses of vehicles, and standard relief time. The model determines the locations of local depots and routing for last mile distribution after an earthquake. The model is extended to a two-stage stochastic program with random travel time to ascertain the locations of distribution centers. Small instances have been solved to optimality in GAMS. A variable neighborhood search algorithm is devised to solve the deterministic model. Computational results of our case study show that the unsatisfied demands can be significantly reduced at the cost of higher number of local depots and vehicles. 相似文献
15.
Bronwen Tucker 《International Journal of Sustainable Transportation》2018,12(1):29-38
In many Latin American cities, rapid motorization and population growth have resulted in unprecedented urban transportation challenges, with lower income populations disproportionately facing constraints to mobility as well as externalities like air pollution, traffic collisions, and the impacts of climate change. The construction of bicycle lane networks has been identified as an effective tool for increasing citizen's mobility and accessibility as well as combating the effects of motorization, but in cities where bicycle lane networks exist, it is not known if they have benefited different income groups equally. This paper assesses the extent to which bicycle lane provisioning has been equitable among neighborhoods in Rio de Janeiro and Curitiba. Both cities were found to have more than twice the supply of bicycle lanes in the wealthiest quintile than the lowest income quintile relative to area and population. A network analysis using a Level of Traffic Stress classification to categorize roads found that wealthier areas have more commercial areas accessible along safer cycling routes. Implications for cycling policy and future research are discussed. 相似文献
16.
Transport provides a range of benefits to society in terms of mobility, access and economic growth. There are however negative impacts of transport, not least in terms of environmental degradation, damage to property, traffic accidents and loss of life. This paper focuses on road traffic accidents, the reduction of which is an important aim of transport policy world wide. The primary objective of this paper is to develop a series of relationships using spatially disaggregated area-level cross-sectional data between different traffic casualties, road traffic speed and road curvature by controlling for other contributing factors associated with area characteristics. The spatial units of the analysis are the 8019 census wards in England. Ward-level casualty data are disaggregated by severity of the casualty (such as fatalities, serious injuries and slight injuries) and by the severity of the casualty related to various road users.The results suggest that increased average speed within a ward is positively associated with total fatalities and serious injuries; and road curvature is found to be negatively associated with road accidents. 相似文献
17.
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. 相似文献
18.
Margaret Kent 《International Journal of Sustainable Transportation》2019,13(2):100-110
As cities across the United States strive to create comfortable bicycle networks for mainstream users, three topics have garnered attention: project prioritization criteria, accessibility to everyday destinations, and social equity. However, these topics have not often been integrated in research or practice. This paper introduces a method to assess the extent to which reductions in “Bicycle Level of Traffic Stress” (LTS) on segments of a citywide bicycle network increase accessibility to supermarkets, pharmacies, banks, and public libraries. Six accessibility performance measures are developed and evaluated for 278 neighborhoods in Baltimore, Maryland using a GIS-based approach. The demographic distributions of accessibility results are further analyzed, focusing on disadvantaged populations. Using a set of 106 proposed bicycle projects, the marginal accessibility gains and cumulative demographic impact across affected neighborhoods are assessed for each project. These results are ranked and crosslisted to identify a set of projects that balance accessibility gains with equity objectives. The prioritization results demonstrate some overlap with the short-term priorities embodied in City of Baltimore's 2015 Bike Master Plan, but they also highlight projects in other areas, specifically those that would serve neighborhoods most disadvantaged in terms of racial segregation, high poverty rates, and low rates of vehicle ownership. 相似文献
19.
Population change and accessibility by road and rail networks: GIS and statistical approach to Finland 1970-2007 总被引:3,自引:0,他引:3
This study analyzes the relation of accessibility by road and railway network to population change between the years 1970-2007 in Finland. Accessibility is evaluated at built-up area unit and municipal levels by potential accessibility analysis and by measuring accessibility to network. Analyses are done in decadal periods by using geographical information systems (GIS) and data about road and railway networks involving digitized speed limits and geometry for each period. Accessibility variables and population change are related by generalized additive models (GAMs). The results indicate that the Finnish population has concentrated to areas with high road-based potential accessibility, especially since the opening in the Finnish economy in the 1990s. The accessibility of railway network was found to have affected the population change in the 1970s, when local level traffic reduced in the entire country, and in 2000-2007, following remarkable investments in long-haul transport. 相似文献
20.
Various geographic units have been used in macro-level modeling. Amongst these units, traffic analysis zones (TAZs) have been broadly employed in many macroscopic safety studies. Nevertheless, no studies questioned the validity of TAZs for crash analysis at the macro-level crash modeling. In this study, we point out several possible problems of TAZs as spatial units for macroscopic safety studies. Current TAZs with homogenous crash rates were combined into new single zones. Then we created ten new zonal systems by different zone aggregation levels. The optimal zonal scale for traffic safety analysis zones (TSAZ) was determined using the Brown-Forsythe test. It was found that the zone system with about 1:2 aggregation was the optimal zone system for macroscopic safety modeling. Thus we develop what we call traffic safety analysis zones (TSAZs) that has the potential of reducing several possible problems of TAZs. Also it was shown that TSAZ based models had better fit compared to TAZ based models. 相似文献