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991.
992.
Amin T. Kiggundu 《Transportation》2009,36(3):275-294
Most major cities across the world today are facing an intractable challenge of financing public transport. In Kuala Lumpur
for example, public transport services are somewhat poor in part because of the failure of major operators to secure ample
funding. Previous funding programs implemented in the city have failed to produce a replicable model for financing public
transport. Due to numerous financial problems and the dismal performance of privately owned transport firms, the State has
in the recent past emerged as a key source of funding for the public transport sector in Kuala Lumpur. This article argues
that, despite the insuperable challenges, prospects for the future funding of public transport in Kuala Lumpur appears to
be good. The article also draws lessons from both Tokyo and Hong Kong. In order to address the funding deficit facing the
public transport industry in the city it is crucial that more viable strategies and policies such as value capture and public–private
sector partnerships are adopted by the urban authorities.
相似文献
Amin T. KiggunduEmail: |
993.
The effect of financial constraints on the optimal design of public transport services 总被引:1,自引:0,他引:1
Recent experience with the design of bus services in Santiago, Chile, seems to confirm Jansson's (1980) assertion regarding
observed planned bus frequency and size being too low and too large, respectively. We offer an explanation based upon the
relation between cost coverage, pricing and optimal design variables. We recall that average social cost decreases with patronage,
which generates an optimal monetary fare below the average operators' cost, inducing an optimal subsidy. Then we compare optimal
frequency and bus size—those that minimize total social costs—with those that minimize operators' costs only. We show that
an active constraint on operators' expenses is equivalent to diminish the value of users' time in the optimal design problem.
Inserting this property back in the optimal pricing scheme, we conclude that a self-financial constraint, if active, always
provokes an inferior solution, a smaller frequency and, under some circumstances, larger than optimal buses.
相似文献
Sergio R. Jara-DíazEmail: |
994.
The current article proposes an approach to accommodate flexible spatial dependency structures in discrete choice models in
general, and in unordered multinomial choice models in particular. The approach is applied to examine teenagers’ participation
in social and recreational activity episodes, a subject of considerable interest in the transportation, sociology, psychology,
and adolescence development fields. The sample for the analysis is drawn from the 2000 San Francisco Bay Area Travel Survey
(BATS) as well as other supplementary data sources. The analysis considers the effects of a variety of built environment and
demographic variables on teenagers’ activity behavior. In addition, spatial dependence effects (due to common unobserved residential
neighborhood characteristics as well as diffusion/interaction effects) are accommodated. The variable effects indicate that
parents’ physical activity participation constitutes the most important factor influencing teenagers’ physical activity participation
levels, In addition, part-time student status, gender, and seasonal effects are also important determinants of teenagers’
social-recreational activity participation. The analysis also finds strong spatial correlation effects in teenagers’ activity
participation behaviors. 相似文献
995.
Fuel-speed curves (FSC) are used to account for the aggregate effects of congestion on fuel consumption in transportation scenario analysis. This paper presents plausible FSC for conventional internal combustion engine (ICE) vehicles and for advanced vehicles such as hybrid electric vehicles, fully electric vehicles (EVs), and fuel cell vehicles (FCVs) using a fuel consumption model with transient driving schedules and a set of 145 hypothetical vehicles. The FSC shapes show that advanced power train vehicles are expected to maintain fuel economy (FE) in congestion better than ICE vehicles, and FE can even improve for EV and FCV in freeway congestion. In order to implement these FSC for long-range scenario modeling, a bounded approach is presented which uses a single congestion sensitivity parameter. The results in this paper will assist analysis of the roles that vehicle technology and congestion mitigation can play in reducing fuel consumption and greenhouse gas emissions from motor vehicles. 相似文献
996.
Behavior of taxi customers in hailing vacant taxis: a nested logit model for policy analysis
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This study models and examines the taxi customers' preferences for hailing vacant taxis on streets. A stated preference survey was conducted to randomly select and interview 1242 taxi customers at taxi stands and pedestrians on streets, who had experiences of taking taxis recently, about their choices under different given hypothetical scenarios. In total, 4968 observations were collected and used for developing the discrete choice models for the analysis. To account for the potential correlations among alternatives, two nested logit models are developed, calibrated, and compared with a standard multinomial logit model in the investigation. The results of likelihood ratio test demonstrate that one of the developed nested logit models is better than the standard multinomial logit model to describe the search behavior of taxi customers. The model results also show that the walking time to and the waiting time at the location for hailing taxis, the extra travel time to the destination because of local circulation for finding a way from the pickup location heading to a passenger's destination, as well as the taxi customers' perceptions for walking to and waiting at taxi stands were found as significant factors to influence their decisions. In addition, the results of market segmentation analysis illustrate the variations in taxi‐search strategies of taxi customers in different districts and regions. Some policy implications on introducing more taxi stands and improving the utilization rates of taxi stands are also discussed. We believe that the proposed models, findings, and discussion are useful for developing micro‐simulation models to evaluate the performance of road traffic networks with taxi services and developing simulation‐based optimization models to answer policy questions related to taxi services. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
997.
船体结构之最佳化设计是一个复杂非线性的混和离散问题,并且要搜寻到全域的最佳值并不容易。在复杂的设计环境下基因演算法(Genetic Algorithm;GA)却可以搜寻到近似的全域最佳值。本文主要是应用基因演算法对T加强板架(Tee stiffened panel)、平板加强板架(flat-bat stiffened Panel)等常用且最具代表性之船体结构件进行最佳化设计,使结构在满足终极破坡限制(ultimate failure constraints)与耐用破坏限制(serviceability failure constraints)等所有限制条件下,求得最佳目标函数值中各设计变之最佳组合。在过程中并考量不同族群大小、变换机率、突变机率因素对最佳化结果的影响。文中是以制造成本为目标函数,其中同时考量材料成本及劳工成本,且所得之结果与连续性线性规则(Sequential Linear Programming;SLP)最佳化结果作了比较。计算的结果显示基因演算法可以有效地与快速地获得最小重量和最低成本的目标。 相似文献
998.
999.
地铁工程施工事故与风险管理 总被引:4,自引:0,他引:4
参考国际隧道协会所建议的分级系统,将2001-2006年间在亚太地区地铁工程施工期间所发生的43个事故,依其后果的严重性分级,以作为发展地下工程风险管理的基础.纳入考量的项目包括人员伤亡、经济损失及对民众生活的影响、工期的延误,以及对交通的影响.并以新加坡政府在尼诰大道灾变后所采取的一连串措施为例,列出地下工程风险管理的要素,勾画出地铁风险管理制度的基本架构. 相似文献
1000.
通过对舰船周围流场信息进行精细化描述,即可从流动机理角度反馈舰船宏观水动力表现的内在本质,而优质的流场测试技术是保证流场精细化描述的必要手段。从舰船流场测试的工程需求出发,根据技术特点梳理现阶段舰船流场试验测试技术的发展现状、应用场景及特性问题,建议从硬件升级与技术融合、算法更迭与功能扩展、数据同化与机器学习等角度切入,以推动流场测试技术朝着综合性、专业化、高效化等方向快速发展。 相似文献