共查询到20条相似文献,搜索用时 15 毫秒
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Intercity passenger trips constitute a significant source of energy consumption, greenhouse gas emissions, and criteria pollutant emissions. The most commonly used city-to-city modes in the United States include aircraft, intercity bus, and automobile. This study applies state-of-the-practice models to assess life-cycle fuel consumption and pollutant emissions for intercity trips via aircraft, intercity bus, and automobile. The analyses compare the fuel and emissions impacts of different travel mode scenarios for intercity trips ranging from 200 to 1600 km. Because these modes operate differently with respect to engine technology, fuel type, and vehicle capacity, the modeling techniques and modeling boundaries vary significantly across modes. For aviation systems, much of the energy and emissions are associated with auxiliary equipment activities, infrastructure power supply, and terminal activities, in addition to the vehicle operations between origin/destination. Furthermore, one should not ignore the embodied energy and initial emissions from the manufacturing of the vehicles, and the construction of airports, bus stations, highways and parking lots. Passenger loading factors and travel distances also significantly influence fuel and emissions results on a per-traveler basis. The results show intercity bus is generally the most fuel-efficient mode and produced the lowest per-passenger-trip emissions for the entire range of trip distances examined. Aviation is not a fuel-efficient mode for short trips (<500 km), primarily due to the large energy impacts associated with takeoff and landing, and to some extent from the emissions of ground support equipment associated with any trip distance. However, aviation is more energy efficient and produces less emissions per-passenger-trip than low-occupancy automobiles for trip distances longer than 700–800 km. This study will help inform policy makers and transportation system operators about how differently each intercity system perform across all activities, and provides a basis for future policies designed to encourage mode shifts by range of service. The estimation procedures used in this study can serve as a reference for future analyses of transportation scenarios. 相似文献
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The impact of global warming and climate change is the most critical challenge of the 21st century. The greenhouse effect caused by technological development and industrial pollution has accelerated the speed of global warming. To effectively reduce global warming and encourage sustainable enterprise development, a comparative analysis approach is used to examine various domestic automotive products which utilize the up-to-date innovative technology. Their contributions to fuel consumption and emissions of the greenhouse gas, carbon dioxide (CO2), are then investigated. This study focuses on technical innovation in a conventional engine and output power. The results indicate that innovative engines (such as the Ford turbo petrol/diesel engine, the EcoBoost/TDCi) have improved energy consumption and CO2 emissions. In addition, an improvement in output power (such as Toyota hybrid vehicles) has also improved energy consumption and CO2 emissions. 相似文献
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In most developed countries motorized transportation is the dominant form of travel for long and short journeys. Transport-related
physical activity (TPA), however, is advocated as an appropriate transport mode for traveling short distances. The purpose
of this study is to explore the associations between private automobile availability, overall physical activity levels, and
TPA engagement in the adult population. A population-representative telephone survey assessed socio-demographics, private
automobile availability, overall physical activity levels, and travel to place of work/study and the convenience shop with
an adult sample (n = 2,000) residing in North Shore City, Auckland, New Zealand in April 2005. The majority of respondents reported unrestricted
(80%) or frequent (12%) private automobile availability. After controlling for covariates, binary logistic regression analyses
revealed those with no private automobile available were less likely to be classified as sufficiently active for health benefits
when compared to respondents with unrestricted private automobile availability. However, this finding was based on a small
minority (4%). Also, those reporting no private automobile availability were more likely to walk or cycle to place of employment
and the convenience shop when compared to those with unrestricted private automobile availability. Similar to other self-report
travel and physical activity survey tools, the questionnaire used potentially did not adequately capture TPA engagement. Future
TPA research needs to incorporate objective measures to address this issue.
相似文献
Hannah M. BadlandEmail: |
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1867年1月,一艘标有"Colorado"字样的太平洋邮政汽轮公司(APL的前身)班轮满载着货物,从旧金山远渡重洋首次登陆中国,140年后,"APL"的名字已在全球海运业掷地有声,并成为全球"多式联运"的先驱者。如今,它仍一如既往地重视中国市场,并且不吝巨资,谋求与中国更深层次的合作。随着全球制造中心的东移, 相似文献
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Roger L. Tobin 《运输规划与技术》2013,36(4):215-223
This paper develops an analytic approach for measuring the effect of vehicle scheduling and of metering methods required to balance entrance rates among stations on lane capacity utilization of automated automobile guideways. The scheduling process at each entrance is represented by a probabilistic model which generates a system of nonlinear equations. The solution of this system yields the maximum steady state input rates at the entrances to the guideway system. The method developed is applicable to network configurations in which a small number of merges must be scheduled for each vehicle before it enters the guideway. It is demonstrated by application to a corridor guideway serving a major activity center during peak inbound demand, and also it is shown how the approach may be extended to more complex networks. 相似文献
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As a response to growing concerns regarding the call for clean energy and its impact on future automobile sales, this study uses a classical factor model and the Peña-Box model to examine the contemporary and time-varying relationships of different brands/models of cars in Taiwan between 2003 and 2007. In this paper, we demonstrate the complementary characteristics of these two analytical and forecasting methods. The results confirm that these two models can derive equally important but different information from the same time series data. Furthermore, the models are a useful marketing tool for discovering the current preferences of car purchasers, as well as their preference changes over time. 相似文献
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《Transportation Research Part B: Methodological》1987,21(4):331-337
This study investigates the influence of adaptive expectations on the purchase of automobiles by income quintile. Through maximum likelihood estimation, it is found that the coefficients of adaptation to income exhibit a trend towards faster rates in the upper quintiles. The effects of a “truncation remainder” and of serial correlation are also noted. 相似文献
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We identify seven areas in which recent research on auto demand has made significant progress. We discuss the importance of these areas in understanding and predicting auto demand and describe the methods that researchers have used to address them. Finally, we identify the issues that this research indicates require further investigation. 相似文献
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Arian Khaleghi Moghadam 《Transportation Research Part D: Transport and Environment》2011,16(8):579-585
This paper compares the outcomes of policies that target vehicle holdings with those that target vehicle usage using data from the US Consumer Expenditure Survey. Results show that a higher price of gasoline shifts vehicle holdings towards more fuel efficient vehicles and reduces the annual demand for miles, whereas imposing a fee on vehicles or a feebate program only shifts vehicle holdings towards more fuel efficient vehicles and has little to no impact on the demand for miles. While it is relatively expensive to reduce CO2 emission through incentive-based policies, achieving any abatement level is more expensive through imposing fees on vehicles than gasoline taxes. In addition, the maximum amount of abatement attainable by a feebate program is relatively small and the same amount could be achieved by imposing a $0.73 gasoline tax per gallon. 相似文献