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1.
It is well known that bicycling in urban areas has beneficial effects on people's health and well-being. On the other hand, urban cycling, especially during the morning and evening commute, may be associated with health and safety risks due to potentially high levels of exposure to air pollution, road noise, and high traffic density. Few studies have, however, measured cyclists' exposure to noise and air pollution simultaneously.The objective of this research is to evaluate cyclists' exposure to air pollution and noise in central city neighbourhoods of Montreal and to identify the impact on exposure of associated local factors such as weather conditions, the day and time, the type of road, bicycle path or lane used and the characteristics of the immediate environment around the cyclist's route.A total of 85 bicycle trips were analyzed, representing 422 km of travel and nearly 25 h of data collection. The mean exposure levels were 70.5 dB(A) for noise and 76 μg/m3 for nitrogen dioxide (NO2). A very weak negative correlation was found between the two measures of exposure (R2 =  0.07, p = 0.005).The results of the spatial regression models show that the morning commute and trips on collector roads and on-street bike lanes and shared bike lanes have significant and positive impacts on exposure to air pollution and noise. On the other hand, some factors are only significant for one or the other of the two types of exposure.  相似文献   

2.
This paper presents a modeling framework developed for the City of Montreal, Canada, and is intended to quantify two indicators that can explain the spatial distribution of traffic-related air pollution at a metropolitan level. The indicators are estimated at the level of the traffic analysis zone (TAZ) and include: (1) the average level of emissions generated per individual and (2) the level of emissions occurring in a zone as a proxy for air pollution exposure. A regional traffic assignment model is extended with capabilities for emission modeling at an individual trip level while taking into account vehicle (type and age) and trip attributes (road type, speed, and volume). We observe that individuals who generate higher emissions from travel tend to reside in areas with lower exposure to traffic emissions while individuals associated with low levels of travel emissions (e.g. travel smaller distances, conduct less trips, and use alternative modes) reside in areas with high levels of traffic pollution. A regression analysis of the two indicators against a set of land-use and socio-economic variables shows that generated emissions per individual are positively associated with car ownership and larger vehicles, while being negatively associated with ownership of newer vehicles, and location in dense and walkable neighborhoods with high levels of commercial land-use. Meanwhile, exposure to emissions is positively associated with dense and walkable neighborhoods and negatively associated with car ownership and larger vehicles. These findings indicate major inequities in the generation of and exposure to traffic-related air pollution.  相似文献   

3.
铁路交通枢纽与城市综合体设计初探   总被引:2,自引:0,他引:2  
通过对国内铁路旅客车站交通枢纽设计模式及国外交通枢纽城市综合体典型案例的分析和总结.提出铁路旅客车站结合物业开发设计并形成交通枢纽城市综合体将是国内铁路旅客车站发展趋势之一的观点,以期对今后铁路旅客车站的建筑设计有所启示。  相似文献   

4.
Defining means to assess safety performance and delve into their causes is one of the current and future challenges of the ATM sector. Following the experiences of the Aerospace Performance Factor by FAA and EUROCONTROL, this research aims to apply the Analytic Hierarchy Process (AHP) in order to build synthetic and user-friendly safety-related indicators. Through the analysis and combination of the safety events over time (accidents, incidents and issues), this model will pinpoint critical situations and will address the interventions of the decision makers.  相似文献   

5.
This paper explores the evolution of airport passenger traffic in Greece over the period 1978–2006. The country is a member of the European Common Aviation Area, but despite air transport liberalisation, spatial concentration of traffic and asymmetry remain high and have not decreased significantly over time. Greece is still short of traffic generated by low-cost carriers especially outside the main metropolitan airports. The paper argues that further dispersion of traffic could be possible primarily in the mainland if low-cost carriers decide to dynamically enter the Greek market. Potential benefits for regional and tourism development should induce policy makers to work towards this direction.  相似文献   

6.
The discovery of explosive devices concealed in air cargo in October 2010 triggered an action plan to strengthen air cargo security in Europe. This paper addresses the potential implications for different actors with respect to the introduction of recent European Union (EU) regulation. The focus is on the legislative efforts to reinforce air cargo security and, in particular, the issue of third countries flights to Belgium. Based on existing literature, a review of the legislation and several interviews with experts and different stakeholders in Belgium, it can be concluded that the current air cargo and mail security framework is not satisfactory. Evidence from both the literature review and the interviews points to a necessary policy paradigm shift towards a risk assessment based security process. Special emphasis should be put on a collaborative industry driven supply chain security and the urgent need to harmonize air cargo security procedures at EU level.  相似文献   

7.
This paper examines the evolution of the geographic concentration of the Brazilian air transport network with a focus on its determinants and possible detachments from the spatial patterns of socioeconomic activity. We develop an econometric framework employing and contrasting the results of Gini, Herfindahl-Hirschman and Theil indexes, with and without normalisation to account for economic and demographic spatial dynamics. Our results suggest that the spatial dynamics of the air network and that of the country's economy and population are strongly tied for the majority of the considered determinants. However, we find suggestive evidence that the time trend after deregulation has produced some asymmetries in the evolution of these dimensions. As such, our analysis presents some implications for airline network planning and regulators, as it offers additional information to be considered for the understanding of extra-economic and extra-demographic impacts which may be inducive of significant changes in air transport markets.  相似文献   

8.
It is generally agreed that government ownership and participation in national carriers and regulated air service agreements can lead to inefficiencies and abuses of market power. This can result in poor carrier performance and service levels, impeding further growth in tourism markets. This paper contrasts this theory with recent case evidence from the Caribbean and the Middle-East. The former represents the mature exotic type beach holiday while the latter is a fast developing religious, cultural and multi-product form of tourism. In both cases multi-step relationships exist between the development of air transport policy and the number of incoming visitors. The strength and significance of these interrelationships are tested using two separate best-fit Structural Equation Models (SEMs) based on a panel data set of a selection of endogenous and exogenous variables for the period 2000-2007. It is found that, despite both regions’ continued government participation in national carriers, only in the Caribbean has this appeared to have resulted in the expected dampening effect on tourism output, whereas a reverse effect was found for the sample of Middle-Eastern states. Focussing on their formidable hub-and-spoke networks, state owned and vertically integrated Middle-Eastern carriers are still encouraged to offer competitive fare and service levels to capture 6th freedom traffic with the growing number of long-stay visitors being one of the main beneficiaries of this.  相似文献   

9.
This paper discusses how various aviation infrastructure service providers have dealt with the fall off in airline traffic following the terrorist attacks in the US on September 11th. It shows that these organizations have relatively high fixed costs and low incremental costs for providing services. As such, small changes in traffic have large impacts on revenue because revenues are generally proportional to activity. However, because of the high component of common and fixed costs, airport and ATS provider costs do not change in proportion to activity. When traffic declines, revenue shortfalls can arise because most airport and ATC systems operate on a simple cost recovery basis. The responses to the events of September 11th have also caused substantial increases in security costs. To the extent these costs are passed forward to system users, they will increase the price of travel and impact patronage further. Airlines also have substantial fixed capacity costs. The declines in traffic are often felt as an erosion of yields and fares as carriers seek to maintain traffic loads for the capacity they are going to operate. In general, the ability to pass along cost increases from providers to airlines or from airlines to passengers depends on relative supply and demand elasticities. Because infrastructure provision is often a monopoly, and the demand for airline services is price elastic, we suggest that most of the cost increases will be borne by the airlines. We also suggest that short-haul flights will be most severely impacted because the fees and taxes are a larger proportion of the fare for these flights. We also examine the extent to which additional infrastructure costs imposed on operators may exacerbate the downturn in their traffic.  相似文献   

10.
This paper presents a comprehensive analysis of air services dynamics during the recent economic crisis. Through a regression analysis, we show that at the country scale, the change in the supply of seats is highly dependent on economic growth, confirming the cyclical nature of the air sector. Hence the crisis of air services has much more affected the USA, Europe and Japan than the rest of the world. However, many countries deviate from this general trend. In a second step, using the existing literature, we explain some of these deviating figures. National specificities and airline strategies seem to influence the intensity of the crisis. We argue that the intensity of the crisis in the US is due to the structural oversupply of the air sector. Through other cases, especially the Middle East, we show that hubbing strategies might reduce the impact of the crisis, or at least make it less dependent upon local economic dynamics. In contrast with other authors, we found no positive impact of the share of low-cost carriers on the supply during the crisis, despite their success in some specific contexts like between Europe and Morocco.  相似文献   

11.
This study analyses the structure of air traffic and its distribution among the different countries in the European Union, as well as traffic with an origin or destination in non-EU countries. Data sources are Eurostat statistics and actual flight information from EUROCONTROL. Relevant variables such as the number of flights, passengers or cargo tonnes and production indicators (RPKs) are used together with fuel consumption and CO2 emissions data. The segmentation of air traffic in terms of distance permits an assessment of air transport competition with surface transport modes.The results show a clear concentration of traffic in the five larger countries (France, Germany, Italy, Spain and UK), in terms of RPKs. In terms of distance the segment between 500 and 1000 km in the EU, has more flights, passengers, RTKs and CO2 emissions than larger distances. On the environmental side, the distribution of CO2 emissions within the EU Member States is presented, together with fuel efficiency parameters. In general, a direct relationship between RPKs and CO2 emissions is observed for all countries and all distance bands. Consideration is given to the uptake of alternative fuels. Segmenting CO2 emissions per distance band and aircraft type reveals which flights contribute the most the overall EU CO2 emissions. Finally, projections for future CO2 emissions are estimated, according to three different air traffic growth and biofuel introduction scenarios.  相似文献   

12.
How can one protect oneself against stress and burnout syndrome? What is the role of human cognitive processes? This study explores the moderated mediation effects of the trait of self-efficacy in a mode of perceived stress and burnout syndrome in a group of Polish air traffic controllers. The first aim of this study was to develop a better understanding of the construct of perceived stress. We proposed a latent variable, called psychological comfort, to clarify the role of self-efficacy in relation: stress and burnout. The second aim was to test the assumptions about the mediating role of self-efficacy in the relationship between stress and burnout via the level of psychological comfort. The most important aim was to investigate whether the direct and indirect associations between stress and burnout were moderated by the level of psychological comfort. For the study, self-report questionnaires were distributed to 609 active air traffic controllers from 18 air traffic control centers of the Polish Air Navigation Services Agency (PANSA). Three hundred forty sets of questionnaires were returned (55.88%) of which 110 were correctly completed (return rate - 18.1%). We formulated 5 hypotheses. Two of them were confirmed: the indirect effect of perceived stress on occupational burnout via general self-efficacy was significant and the indirect relationship between perceived stress and occupational burnout would be different for air traffic controllers characterized by various levels of psychological comfort. The study emphasizes the role of certain human cognitive resources which may play a role in the relationship between stress and burnout: self-efficacy, perceived stress, and psychological comfort. There are important practical conclusions from the research. Knowing about the level of psychological comfort helps to plan better actions to protect against the negative impact of chronic stress on cognitive functions and against the development of clinical symptoms of burnout syndrome.  相似文献   

13.
This paper examines the cost structures of the leading integrated air cargo carriers, FedEx Express and UPS Airlines. A total cost model is estimated for the two carriers using quarterly data on domestic operations and costs over a nine-year period (2003–2011). The estimated model indicates that the integrated industry exhibits increasing returns to traffic density and constant returns to scale. Accounting for carrier-specific differences in cost structure and network size, FedEx Express is found to be more cost-efficient than UPS Airlines. Looking at the carriers individually, UPS Airlines exhibits substantial economies of traffic density and constant returns to scale while FedEx Express' cost structure is characterized by weak economies of density and constant returns to scale. The combined effect of returns to density and returns to scale on the cost structures of integrated carriers is captured by economies of size. Both FedEx Express and UPS Airlines exhibit economies of size, indicating that carriers in the integrated industry can be more cost efficient by making appropriate adjustments to their network size as their output grows. Moreover, the relative cost-efficiencies of the carriers are reversed when their network-size differences are not controlled.  相似文献   

14.
Diary studies have become increasingly popular in the field of transport research since their first recorded use just over 60 years ago, allowing collection of data not only on patterns of travel, but also on the full context for travel. However, few have incorporated recording of people’s use of new technologies, specifically, the Internet. This paper discusses a methodology, the accessibility diary, designed so to do. With a focus upon usability for participants and utility for researchers, the paper describes the diary design in full, assessing its efficacy with reference to focus group, interview and questionnaire data, alongside lessons from the analysis. The paper concludes with a consideration of the dilemma facing transport researchers: the wish to collect ever more complex information to advance understanding versus the need to develop methodologies that are simple to use, to maximise data quality and response rates.  相似文献   

15.
The COVID-19 crisis has become the most intense and long-lasting in the history of aviation. There is already a significant literature on the immediate impact of the outbreak, as well as on speculation on the future evolution of the industry. This paper seeks to contribute to this discussion by assessing a year into the crisis the demand related aspects and passenger behavioural impacts of the pandemic. Specifically, the paper aims to identify discrete market segments of air passengers according to their shared attitudes and preferences about air travel in light of the COVID-19 crisis, as well as past behaviour and future travel intentions. To achieve this, we analyse data from a large (n = 2096) online questionnaire survey of air passengers in Norway. The cluster analysis identifies four distinct passenger segments, with each displaying varying attitudes, behaviours, and levels of concern about air travel. One of these groups, described as the ‘Apprehensive Elders’, were identified as having the highest level of concern about flying, and subsequently showed a sharp decline in their intention to travel in the future. Another group, termed the ‘Cautious Commuters’, showed similarly enhanced levels of concerns about flying, but maintained a high propensity to fly following the pandemic despite these concerns. Regarding possible interventions to increase confidence in flying in the future, across all segments the data shows a clear preference for more ‘traditional’ active interventions, including wearing of face masks and enforcement of physical distancing, over and above passive or technological interventions. Norway represents a valuable case as a possible signal for future policy and practice in relation to the recovery of air travel following the pandemic. The findings have important implications for air transport managers and decision makers in terms of managing the perceptions and expectations of different passenger groups as air travel begins to return.  相似文献   

16.
We have realized that the quantitative analysis of safety data is an advanced technology of unsafely events research. Based on the analysis and statistical research on Air Traffic Control irregular events of 2011 using The Threat and Error Management (TEM) model, we have established the Bayesian network model to perform a precise quantitative analysis on the relevance between the threat, error and undesired states in Air Traffic Control operation. This analysis, based on the prior probability, obtained the relevance of the three kinds of safety information above through studying the respective posterior probabilities of threats or errors under undesired states. The result showed that the relevance of controller communication error and undesired states was 75%, and the relevance of Air Traffic Control threats as well as communication error with undesired states in Air Traffic Control was 13.3% and 25%, respectively. Therefore, this research method is of great significance for improving the mechanism of the Air Traffic Control operation risk management.  相似文献   

17.
IntroductionTraffic jams, congestion and pollution demand sustainable modes of transport. To increase the appeal of cycling, bicycle-users' perceptions and needs should be acknowledged by decision-makers. However, traditional transport planning mainly focuses on quantitative, infrastructural data. To address this gap, this study explores to what extent decision-makers are aware of cyclists' needs and perceptions. Furthermore, the study compares the assessments about cycling of decision-makers and cyclists in the city of Leipzig, Germany.MethodsQualitative Interviews with 13 cyclists and similarly structured interviews with 6 experts from politics and planning were compared using qualitative content analysis. Two main topics were examined: (1) the reasons for cycling and (2) the perceived environment (built, natural and individually perceived). To integrate the spatial context, the interviewees draw sketch maps which were analyzed and compared using geo-information systems.ResultsExperts assume that main roads with cycling infrastructure are decisive for fast and safe cycling and cyclists agree with this statement. However, cyclists further refer to the positive effects of green spaces, the experience of the natural environment (e.g. fresh air) as well as the healthy and recreational effect of cycling. Cyclists prefer taking side roads and are prepared to use detours to integrate the natural environment and avoid traffic jams, noise and air pollution – these aspects were rarely acknowledged by decision-makers.DiscussionWe conclude that urban planners need to involve cyclists' perceptions more explicitly. Integrating cyclists' experiences in planning processes using sketch maps and interviews are beneficial, complementing quantitative approaches to enhance the understanding of cyclist behavior. The findings are essential to stress the importance of participatory approaches in urban planning to promote a sustainable, healthy and environmentally friendly urban development appropriate to citizens' needs.  相似文献   

18.
In the United States, the goal of essential air service (EAS) is to provide a minimum level of air transport service from smaller, often remote communities to the national network. While supporters of EAS tout the economic benefits of connecting rural and isolated communities, critics cite high costs, low use and antiquated eligibility requirements as factors which compromise the value of the program. In this paper, a comprehensive database of US airports is combined with network analysis techniques and a geographic information system to evaluate population access (at the census tract level) to EAS airports for 2006. Results suggest that redundant coverage of EAS market areas by alternative Federal Aviation Administration designated hub airports can contribute to EAS airport market leakage and that alternative definitions of EAS community eligibility have the potential to dramatically increase programmatic efficiency and reduce federal monies spent on EAS subsidies.  相似文献   

19.
In Africa, the Yamoussoukro Decision (YD) to date remains the single most important air transport reform policy, the continent-wide implementation of which remains pending. This study employs the Air Liberalisation Index (ALI), developed by the Word Trade Organisation (WTO) Secretariat, to measure the impact of each of the seven quantifiable market access features of South Africa's aviation policy in Africa on air passenger traffic flows. A fixed one-way panel regression technique was applied to panel data, representing five air transport markets: intra-African, the SADC, East African, West African and North African over two time periods (2000–2010; 2006–2010). The results proved to be significant in three markets, intra-African, the SADC and East African and provide new insights into the relationship between air passenger traffic flows and aviation policy in the South African – intra-African and regional contexts.  相似文献   

20.
Engineering and improved road safety education has resulted in an overall decrease in road traffic accident numbers in Christchurch, New Zealand. The temporal trends of crash data from 1980 to 2004 reveal that lowering of crash rates is not occurring at a uniform rate throughout the day, with comparative increases in crash rates occurring during morning rush hour, and during the ’school run’. No spatial clustering around schools was identified. This suggests that policies to reduce school travel related road accidents need to be focused on reducing overall traffic levels rather than focusing geographically on areas in the immediate vicinity of schools.  相似文献   

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