首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Under the United States federal Clean Air Act Amendments of 1977, states must implement transportation system management (TSM) tactics in urban areas that have not attained national ambient air quality standards for carbon monoxide and photochemical oxidants. This paper provides a preliminary assessment of the effectiveness and feasibility of using TSM tactics to improve air quality. Based on this assessment, the authors conclude that TSM measures should be effective in eliminating localized carbon monoxide problems, but that such measures are not likely to contribute significantly toward reducing regional oxidant levels. In addition, because most individual TSM tactics can have only marginal impacts on regional motor vehicle emissions, coordinating the planning and implementation of a portfolio of TSM measures will be an essential element of an effective TSM program for improving air quality.  相似文献   

2.
Evaluating locational accessibility to the US air transportation system   总被引:2,自引:0,他引:2  
Although there are hundreds of airports that support commercial air passenger traffic in the United States (US), not all areas are equivalently served by the commercial air transportation system. Locations in the US differ with respect to their level of access to the commercial air network and their overall accessibility within the system. Given the complexity of the domestic commercial air passenger network and supporting infrastructure, past research has only been able to provide a limited assessment of locational accessibility within the United States. To address these complexities, this paper proposes a new metric that incorporates measures of access to air transport as well as accessibility within air transportation networks. Using a comprehensive dataset on scheduled airline service, the developed approach is then applied to the US domestic commercial passenger air transportation network to explore geographic differentials in accessibility. Results suggest marked differences between core-based statistical areas throughout the US.  相似文献   

3.
Nahmias-Biran  Bat-hen  Shiftan  Yoram 《Transportation》2020,47(5):2287-2305
Transportation - The capability approach (CA) is a theoretical framework that emphasizes the moral significance of individuals’ capability to achieve outcomes that they value and have reason...  相似文献   

4.
The aviation community is increasing its attention on the concept of predictability when conducting aviation service quality assessments. Reduced fuel consumption and the related cost is one of the various benefits that could be achieved through improved flight predictability. A lack of predictability may cause airline dispatchers to load more fuel onto aircraft before they depart; the flights would then in turn consume extra fuel just to carry excess fuel loaded. In this study, we employ a large dataset with flight-level fuel loading and consumption information from a major US airline. With these data, we estimate the relationship between the amount of loaded fuel and flight predictability performance using a statistical model. The impact of loaded fuel is translated into fuel consumption and, ultimately, fuel cost and environmental impact for US domestic operations. We find that a one-minute increase in the standard deviation of airborne time leads to a 0.88 min increase in loaded contingency fuel and 1.66 min in loaded contingency and alternate fuel. If there were no unpredictability in the aviation system, captured in our model by eliminating standard deviation in flight time, the reduction in the loaded fuel would between 6.12 and 11.28 min per flight. Given a range of fuel prices, this ultimately would translate into cost savings for US domestic airlines on the order of $120–$452 million per year.  相似文献   

5.
Urban agglomerations in Tokyo and Osaka in post-war period are largely attributable to the policies underlying the four National Development Plans implemented in that period. These policies, which were originally intended to achieve an effect on the opposite of agglomeration, relate primarily to the high-speed transit network known as the Tokaido shinkasen and the expressway segments linking the Kanto and Kansai regions. For the purpose of capturing the historical scenario of regional agglomeration, we have formulated a long-term macro-econometric model from 1950–85, with 5-year simulation cycles. This constitutes an employment distribution block, an input-output block, and an inter-prefectural activities block, incorporating all major macro-variables. In an earlier stage of this research the model was calibrated and the total tests upon all formulations were completed. Ascertaining that the accuracy of the model is well within permissible limits, an evaluation of policy scenarios due to the delay in the introduction of the shinkansen on the Tokaido line, has been conducted. Results indicate that Tokyo grows much less rapidly than in reality, Osaka maintains the same rate of growth, and the other areas show a substantial growth by 1985. In the present version, we improve on the model with respect to its qualitative performance by relaxing the exogeneity of national employment and GNP to allow for the evaluation of these policy variables. In completing these final tests on the model, we are able to confirm the validity of the model by demonstrating its accuracy to be in a satisfactory range. In a case study, the policy areas that have contributed to the present distribution of development have been explored in detail. Comparative policy transformations, necessary to achieve the opposite effects to agglomeration, are discussed.  相似文献   

6.
This study investigated whether the availability of transportation alternatives for older drivers is a determinant of the decision to cease driving. We recruited participants from a total of 7827 drivers aged 69 years or older living in Ibaraki Prefecture, Japan who were scheduled to renew their driving license between February and April 2011. In November 2010, we distributed questionnaires to collect data on predictors of driving cessation, and again in December 2012 to determine who had actually ceased driving. The relative impacts of factors related to driving cessation were then estimated. Of the 3089 respondents, 157 did not renew their license. The strongest determinants of this decision were having been advised to stop driving and if they had developed less confidence in their ability to drive safely. Even so, respondents were far more likely to have actually stopped driving if they were sure that someone else was available to provide a ride when they needed one. The final decision to stop driving is strongly influenced by personal convenience based on private transport, especially amongst drivers who have been advised to stop. The availability of public transport alternatives is not as important a factor in this decision.  相似文献   

7.
The persistence of environmental problems in urban areas and the prospect of increasing congestion have precipitated a variety of new policies in the USA, with concomitant analytical and modeling requirements for transportation planning. This paper introduces the Sequenced Activity-Mobility Simulator (SAMS), a dynamic and integrated microsimulation forecasting system for transportation, land use and air quality, designed to overcome the deficiencies of conventional four-step travel demand forecasting systems. The proposed SAMS framework represents a departure from many of the conventional paradigms in travel demand forecasting. In particular, it aims at replicating the adaptative dynamics underlying transportation phenomena; explicitly incorporates the time-of-day dimension; represents human behavior based on the satisficing, as opposed to optimizing, principle; and endogenously forecasts socio-demographic, land use, vehicle fleet mix, and other variables that have traditionally been projected externally to be input into the forecasting process.  相似文献   

8.
In this study, passengers’ willingness to pay (WTP) for and willingness to accept (WTA) improved public transportation and shift to public transportation in Malaysia were examined. Specifically, this study aimed to determine the factors or transport attributes that affect passenger WTA and WTP to shift to public transportation. The adopted methodology was based on a contingent valuation (CV) survey, which was conducted on a representative sample of a cross section in residents of Kajang, in Malaysia. This CV primary survey elicited the demand of passengers for improved public transportation. The spike model was adopted to avoid estimation errors caused by a large percentage of respondents who were unwilling to pay and accept at all. The estimation results showed that the best reduction rate for both travel time and cost was 45% among other amounts that range from 15% to 75%. The best parking cost increment was US$0.30 and the average WTP is US$0.68.  相似文献   

9.
The asymmetric effects of service quality on international travelers' airline choice behavior were investigated in this paper. The linear structural equation modeling system was first applied to quantify passengers' perceptions of service quality provided by airlines, which were then used as the input variables of the asymmetric response model developed to capture international travelers' airline decision. Their asymmetric responses to various service quality of airlines were assumed to be either gains or losses with respect to their reference points. The results showed that the asymmetric response model performs better than the traditional logit models that capture only symmetrical effects.  相似文献   

10.
Improving air quality across mainland China is an urgent policy challenge. While much of the problem is linked to China’s broader reliance on coal and other fossil fuels across the energy system, road transportation is an important and growing source of air pollution. Here we use an energy-economic model, embedded in a Regional Emissions Air Quality Climate and Health (REACH) integrated assessment framework, to analyze the impacts of implementing vehicle emissions standards (ES) together with a broader economy-wide climate policy on total air pollution in five species and 30 Chinese provinces. We find that full and immediate implementation of existing vehicle ES at China 3/III level or tighter will significantly reduce the contribution of transportation to degraded air quality by 2030. We further show that road transport ES function as an important complement to an economy-wide price on CO2, which delivers significant co-benefits for air pollution reduction that are concentrated primarily in non-transportation sectors. Going forward, vehicle emissions standards and an economy-wide carbon price form a highly effective coordinated policy package that supports China’s air quality and climate change mitigation goals.  相似文献   

11.
This study examines the concentrations of air pollutants in passenger carriages on a number of lines of the Beijing railway transit system differentiating between services with and without air conditioning. In-train air quality monitoring found PM10 concentrations are extremely high compared with other cities. Integrated factor assessment results show that the in-train air quality in the ground railway transit system where there is air conditioning is more acceptable than in the underground system.  相似文献   

12.
This study investigates the asymmetric effects of gasoline prices on public transportation use in Taiwan. The empirical results obtained are as follows. First, we verify that gasoline price is an important determinant of transit demand. Gasoline prices have significantly positive effects on bus and mass rapid transit (MRT) use. Second, MRT ridership is more sensitive than bus and railway ridership to gasoline price and income. In the face of oil prices escalation and economic growth, the MRT system should have higher priority in public transportation planning. Third, the effects of gasoline prices on bus and MRT use are asymmetric. Bus and MRT use increases faster when gasoline prices rise than it decreases when gasoline prices fall. The transit agencies should adjust operating strategies faster in the rising of oil prices than in the falling of oil prices. It is important for transit planning to use oil prices as signals and increase the flexibility of operation in dealing with the changes in ridership. Some strategies, such as enhancing the availability of transfer information and updating transit information timely, are helpful to move passengers efficiently.  相似文献   

13.
Welfare services such as healthcare and education are commonly recognised as determinants of physical quality of life indices during the early phases of development in the third world. In order to benefit from these services, it is important that the general public have the mobility means to access welfare provision centres. However, very low vehicle ownership under the conditions of low per‐capita incomes and large shares of population living in deep rural areas prevent the masses from accessing such services, thereby retarding the process of social development, which is reflected in the very poor physical quality of life indices in low‐income countries. Public transportation could offer a viable and affordable solution to this apparent ambivalence. It could permit mobility for poor masses in spite of low per‐capita vehicle ownership enabled by the national income levels. The present research demonstrates this strategic niche through an econometric examination of the evolution of the physical quality of life indices such as maternal mortality, infant mortality and literacy as against the healthcare, education and affordable mobility proxies in post‐independent Sri Lanka. The country, which was then referred to as Ceylon, is often cited as a rare example of achieving social inclusion and reduced marginalisation and thereby a high social welfare standing, in spite of relatively poor per‐capita income levels. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

14.
This article explores the effects of perceived green value, perceived green usefulness, perceived pleasure to use, subjective norms and perceived behavioral control on green loyalty to a public bike system. The mediators between perceived green value and green loyalty and a moderator of general attitude toward protecting the natural environment are also discussed. The aim of this research was to understand how to establish green loyalty via the other dimensions based on the sustainable modified technology acceptance model (modified TAM), the theory of planned behavior (TPB), and a moderator. The findings reveal that perceived pleasure to use and subjective norms have the strongest power to influence loyalty for both users and non-users. The implications of this finding are that fun in people’s lives has a strong influence on sustainable continuous use of public bikes, and that subjective norms are more effective for non-users. In addition, environmental attitude has stronger moderating effects for non-users than for users on perceived green usefulness, perceived pleasure and subjective norms. Therefore, governmental policies should promote the attitude of protecting the natural environment, perceptions of pleasure, and subjective norms so as to increase green loyalty to public bike-sharing.  相似文献   

15.
A transit service quality study based on cluster analysis was performed to extract detailed customer profiles sharing similar appraisals concerning the service. This approach made it possible to detect specific requirements and needs regarding the quality of service and to personalize the marketing strategy. Data from various customer satisfaction surveys conducted by the Transport Consortium of Granada (Spain) were analyzed to distinguish these groups; a decision tree methodology was used to identify the most important service quality attributes influencing passengers’ overall evaluations. Cluster analysis identified four groups of passengers. Comparisons using decision trees among the overall sample of all users and the different groups of passengers identified by cluster analysis led to the discovery of differences in the key attributes encompassed by perceived quality.  相似文献   

16.
Diurnal cycles of ground-level ozone and its precursor NOx concentrations stem from and reflect complex temporal patterning of many underlying factors, including transportation emissions. Investigating the complexity of diurnal ozone/NOx cycles at a finer temporal resolution allows a better understanding of ozone dynamics and helps in designing ozone control strategies. This study applied functional data analysis techniques to hourly resolved ozone and NOx measurement data from the 1997 Southern California Ozone Study. Functional analysis of variance on diurnal ozone/NOx cycles for urban and rural monitoring sites confirmed, in a new continuous functional form, the ozone weekend effect. Functional data analysis also allows for a direct examination of day-of-week effects on ozone formation/destruction rates. Comparisons of Sunday ozone rates to those on weekdays demonstrate earlier, faster, and longer duration of ozone accumulation on Sunday. The results are further interpreted from the transportation emissions perspective using hourly resolved weigh-in-motion traffic data.  相似文献   

17.
The work presented in this paper is aimed at investigating the economic effects of air pollution from mobile sources on public health in Lebanon. It is part of the effort to implement MedPolicies Initiative of the Mediterranean Environmental Technical Assistance Program (METAP III whose objective is to encourage sustainable economic growth through the integration of environmental concerns in economic and fiscal policy-making in 13 Mediterranean countries. In each of these countries, the most significant sector is investigated. The transport sector in Lebanon is the predominant sector in terms of energy consumption and its associated air pollution impacts. A multidisciplinary effort is carried out for this purpose in which measurement and modeling of air pollution caused by motor vehicles, determination of the quantitative relationship between pollutants and public health, and an estimation of the effects of air pollution on public health have been carried out. This study is concluded by highlighting the mitigation options applicable for the country and for similar developing nations from social and economic points of view.  相似文献   

18.
In this paper, the crowding effect in a transit vehicle is modeled in a time-expanded network that considers the daily variation in passenger flows. The study models the daily variation of in-vehicle crowding in a real large-scale transit system. A transit assignment for this real network is modeled and implemented by constructing a crowding cost function that follows the valuation of crowding and by using the reliable shortest path finding method. The direct application of the crowding model to a real network for the Utah Transit Authority indicates that crowd modeling with multi-user classes could influence public transportation system planning and affect the revenues of transit agencies. Moreover, the addition of the disutility factor, crowding, does not always appear to cause an increase in disutility for transit users.  相似文献   

19.
Evaluating the impact of public mass transit systems on real-estate values is an important application of the hedonic price model (HPM). Recently, a mathematical transformation of this approach has been proposed to account for the potential omission of latent spatial variables that may overestimate the impact of accessibility to mass transit systems on values. The development of a Difference-in-Differences (DID) estimator, based on the repeat-sales approach, is a move in the right direction. However, such an estimator neglects the possibility that specification of the price equation may follow a spatial autoregressive process with respect to the dependent variable. The objective of this paper is to propose a spatial Difference-in-Differences (SDID) estimator accounting for possible spatial spillover effects. Particular emphasis is placed on the development of a suitable weights matrix accounting for spatial links between observations. Finally, an empirical application of the SDID estimator based on the development of a new commuter rail transit system for the suburban agglomeration of Montréal (Canada) is presented and compared to the usual DID estimator.  相似文献   

20.
Changes in the use of public transportation for commuting in the United States are examined here. Between 1960 and 1980, census data for 25 large metropolitan areas suggests that commuting by public transportation has declined both in importance relative to other modes and in the absolute numbers of commuters using transit. A statistical analysis suggests that the numbers of public transportation commuters are very closely related to the number of central business district (CBD) employees, rather than to overall metropolitan area size. Metropolitan areas with fixed rail services experienced greater than average declines in ridership.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号