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901.
Do changes in neighborhood characteristics lead to changes in travel behavior? A structural equations modeling approach 总被引:5,自引:2,他引:3
Suburban sprawl has been widely criticized for its contribution to auto dependence. Numerous studies have found that residents
in suburban neighborhoods drive more and walk less than their counterparts in traditional environments. However, most studies
confirm only an association between the built environment and travel behavior, and have yet to establish the predominant underlying
causal link: whether neighborhood design independently influences travel behavior or whether preferences for travel options
affect residential choice. That is, residential self-selection may be at work. A few studies have recently addressed the influence
of self-selection. However, our understanding of the causality issue is still immature. To address this issue, this study
took into account individuals’ self-selection by employing a quasi-longitudinal design and by controlling for residential
preferences and travel attitudes. In particular, using data collected from 547 movers currently living in four traditional
neighborhoods and four suburban neighborhoods in Northern California, we developed a structural equations model to investigate
the relationships among changes in the built environment, changes in auto ownership, and changes in travel behavior. The results
provide some encouragement that land-use policies designed to put residents closer to destinations and provide them with alternative
transportation options will actually lead to less driving and more walking.
Xinyu (Jason) Cao is a research fellow in the Upper Great Plains Transportation Institute at North Dakota State University. His research interests include the influences of land use on travel and physical activity, and transportation planning. Patricia L. Mokhtarian is a professor of Civil and Environmental Engineering, Chair of the interdisciplinary Transportation Technology and Policy graduate program, and Associate Director for Education of the Institute of Transportation Studies at the University of California, Davis. She specializes in the study of travel behavior. Susan L. Handy is a professor in the Department of Environmental Science and Policy and Director of the Sustainable Transportation Center at the University of California, Davis. Her research interests center around the relationships between transportation and land use, particularly the impact of neighborhood design on travel behavior. 相似文献
Susan L. HandyEmail: |
Xinyu (Jason) Cao is a research fellow in the Upper Great Plains Transportation Institute at North Dakota State University. His research interests include the influences of land use on travel and physical activity, and transportation planning. Patricia L. Mokhtarian is a professor of Civil and Environmental Engineering, Chair of the interdisciplinary Transportation Technology and Policy graduate program, and Associate Director for Education of the Institute of Transportation Studies at the University of California, Davis. She specializes in the study of travel behavior. Susan L. Handy is a professor in the Department of Environmental Science and Policy and Director of the Sustainable Transportation Center at the University of California, Davis. Her research interests center around the relationships between transportation and land use, particularly the impact of neighborhood design on travel behavior. 相似文献
902.
903.
Jonathan L. Gifford 《国际交通安全学会研究报告》2010,34(1):1-8
This paper examines American attitudes about the role and structure of government and how those attitudes affect the safety potential of ICT-based road safety technologies. It examines these attitudes in the context of 3 current intelligent transportation systems (ITS) initiatives: IntelliDriveSM, active traffic management (ATM), and automated enforcement. It concludes that cultural attitudes have a strong influence on the acceptance of such systems, and provides suggestions for how such systems might be implemented successfully. 相似文献
904.
通过分析县乡公路网建设与社会经济发展的相互关系,结合县乡公路网的特点,从经济发展度、连通度和导向度三个方面定义交通小区的重要度,建立基于区位重要度的县乡公路网交通生成模型。永定县县乡公路网规划实例使得该方法的合理性和有效性得到了验证。 相似文献
905.
906.
907.
在拥堵的高速公路上,合乘车辆(HOV)车道是一种高效环保的交通方式. 虽然HOV车道广受采纳,但该系统的利用效率受到质疑. 加州在全州范围内 采取了一项允许混合动力车辆使用HOV车 道的政策,以期通过鼓励驾驶员使用省油汽车来减少尾气排放,同时通过更有效地利用HOV车道的剩余通行能缓解交通拥挤. 加州橘县高速公路的路网用于研究 该政策的影响及有效性. 研究方法结合使用传统的规划模型来估计交通需求及校准的微观仿真模型来评价系统性能. 通过对系统整体性能、车道服务水平和空气质量 三方面的分析,结论表明此政策对在高峰时段没有剩余通行能力的HOV车道带来严重的负面影响. 为保证HOV车道服务质量不明显下降还能减少排放,该政策最多允许50 000辆在加州注册的混合动力车辆使用HOV车道. 相似文献
908.
Chao Lü 《西安交通大学学报(英文版)》2010,22(2):71-76,82
In this study, based on its enhancement effect on resonance light scattering (RLS) of fluorosurfactant (FSN)-capped gold nanoparticles (GNPs), we reported a simple approach for the rapid sensing of captopril. Under optimum conditions, the lowest detectable concentration of captopril through this approach (S/N=3) was 0.01μg/mL. The calibration curve was linear over the range of 0.08-4.0μg/mL for the detection of captopril. The recoveries of captopril were found to fall in the range between 99% and 100%. We have validated the applicability of our method through the analyses of captopril in pharmaceutical formulations. Good agreements were obtained for the determination of captopril between the present approach and official method. 相似文献
909.
目的 从扩增稳定性、扩增效率以及可靠性等多方面评估实时定量PCR(RtPCR)反应小体积的可行性,同时确定适合小体积体系的模板量.方法 将实验分为10、15、20μL 3个体积组,每组分别采用0.1、0.2、0.3、0.4μL的大鼠cDNA为模板,进行大鼠β-actin mRNA的RtPCR扩增.通过扩增曲线和熔解曲线考察反应的稳定性,以梯度模板拟合标准曲线获得反应的扩增效率,其线性相关程度反映模板量是否合适.另外,构建大鼠降植烷诱导的关节炎(pristane-induced arthritis, PIA)模型,采用选定的反应体系,分别对模型组和正常组大鼠脾脏TNF-α mRNA进行扩增,通过TNF-α的相对表达趋势反映小体积扩增的可靠性.结果 在大鼠β-actin mRNA的RtPCR扩增中,10、15、20μL 3个体积组均能特异稳定地进行扩增,并保证高扩增效率.而且每个体积组中的模板梯度表现出很好的线性相关趋势.同时选用10μL和20μL反应体积、0.2μL模板对关节炎大鼠脾脏进行TNF-α mRNA扩增,结果一致表现出了预期的显著性上调.结论 实验证实10μL、15μL等小反应体积应用于RtPCR扩增中是可行的,具有较好的稳定性和可靠性,同时0.1~0.4μL cDNA模板在3种体系的合适模板范围内.这种较小的PCR反应体积,不仅节省了试剂和实验材料,对一些来之不易的临床标本尤为重要,也利于高通量大规模的RtPCR检测的实现. 相似文献
910.
In fuel-cell-powered vehicles, the fuel-cell system requires a thermal-management subsystem to dissipate heat released during
the reaction of hydrogen with oxygen. When the stack generates power at a high rate, a large amount of heat is also generated.
If cooling by the radiator is insufficient, a supplementary stack-cooling system is needed to maintain a safe operating temperature.
In this study, the performance of a CO2 air-conditioning unit for stack cooling was investigated under various conditions, and the relationship between cabin cooling
and stack cooling was also studied. The coefficient of performance (COP) increased from 1.9 to 2.4, with an increase in cabin-air
inlet flow rate from 0 to 8 m3/min. When the air-conditioning unit was turned off, the cooling capacity of the stack cooler was increased; correspondingly,
as the cabin-cooling capacity was increased, that of the stack cooler decreased. With an increase in ambient-air inlet temperature
from 38°C to 45°C, the COP decreased by 24%. Additionally, both the stack-cooling capacity and cabin-cooling capacity were
decreased by about 12% and 16%, respectively, due to reduced heat transfer in the gas cooler as the ambient air inlet temperature
was increased. It is expected that the experimental results can serve as a resource in designing a stack-cooling system using
a CO2 air-conditioning unit to enhance stack power generation and efficiency. 相似文献