Light rail transit: Cost and output

Growing concerns about environment, oil depletion, and traffic congestion call for a fresh look at mass transit—specifically non-polluting, low noise, nonoil-consuming, high-speed electric transit. This article attempts to relate cost to output, both for light rail and the alternative transit mode, i.e., the express bus. For that purpose a simple algebraic framework is developed, tailored to data obtained from a study of alternative transit modes in the Pittsburgh South Hills corridor. The data were prepared by De Leuw Cather and Company for the Port Authority of Allegheny County and were published by the U.S. Department of Transportation in a recent study of the state of light-rail art. The article finds the volume of output at which, considering cost alone, a mass-transit authority would be indifferent between light rail and express buses. At the end, noncost factors are considered.     

公交实时信息化服务对乘客出行行为意向影响

为了解城市公交信息化服务对公交乘客出行方式转移的影响,以上海市杨浦区为例,进行关于公交信息化服务下乘客出行方式转移的调查,获取个人属性、公交出行经历、公交出行评价、出行方式转移意向以及公交信息服务需求等信息。从公交信息使用者角度,重点关注公交信息化服务对乘客出行方式转移的影响,分别构建信息化服务情境下(公交到站时间与计划出发时间相差过大和车辆未在提示的时间内到达)的公交出行方式转移二项logit模型。模型结果表明:乘客平均候车时间、是否经常使用公交到站服务、是否有道路拥挤车辆未按时进站等原因而产生出行延误的经历、公交信息准确性评价与是否有必要提示同公交线路连续班次的到站时间等因素对不同情景下的乘客出行方式转移具有显著影响。     

城市轨道交通接运公交规划方法与实践

文章通过对国外轨道交通接运公交规划方法的研究,提出了适合于广州的轨道交通接运公交规划标准,并建议在广州市轨道交通四号线交通衔接规划中加以实践。     

分析广州快速公交系统建设

在分析快速公交系统基本要素的基础上,结合国内外成功经验,提出广州快速公交系统的定位。肯定广州快速公交系统的积极作用在于短期内缓解大城市交通拥挤问题,提出其隐患在于该系统与城市土地的合理利用的矛盾、与其它公交方式的合理衔接、技术保障能否实现等。     

Nontechnological innovation in urban transit: A comparison of some alternatives

Transit alternatives, including conventional technology used in innovative ways, are compared on the basis of full costs (capital and operating costs plus user time costs). Bus wagon jitneys are estimated to have lower full costs than conventional buses for short-haul, low-density residential collection or inner-city circulation, particularly at higher travel time values. Rail rapid transit has much higher full costs than express bus for suburban CBD commuters. Rail's much higher capital and operating costs buy virtually identical user time costs for the entire commuter trip.     

浅谈城市快速公交系统的规划与设计

本文结合广州市城市快速公交系统的规划与设计,对城市快速公交系统的线路组织形式、与普通公交线路的整合、道路断面、车站四个方面对规划设计进行了探讨,为城市快速公交系统在我国的应用和发展提供借鉴。     

合肥市快速公交系统(BRT)换乘架构设计研究

快速公交系统(BRT)是一种融合了先进的公交技术、公交运营新观念和管理技术于一体的系统。这个系统可以提供先进的运输服务,相当于快速轻轨运输系统。本文从合肥市应用BRT解决公共交通问题的实际需求出发,对该系统的换乘架构进行设计分析,为更好的BRT系统提供参考。     

Minibuses in urban transportation

Bus-route simulations suggest that minibuses could not survive in North America or Europe if driver wages equal those currently paid mass-transit bus drivers. If minibuses pay taxi-driver wages and standard buses pay current wages, however, minibuses would yield slightly and appreciably lower urban travel costs than standard buses given respectively marginal-cost and current prices for road services. Scale economies justify markedly smaller subsidies for minibuses than for standard buses. Underpriced road services justify substantial subsidies and preferential access to road capacity for both minibuses and standard buses.     

公共交通中的数据结构算法与实现分析

近年来,我国城镇化速度不断加快,城市人口不断增多,交通拥堵问题日益突出。公交是城市交通的主力军,通过这一主力军来解决城市交通拥堵问题是必由之路,因此公交数据结构算法与实现问题就显得极其重要。现以GIS为基础,公交数据结构模型为出发点,具体论述了公交数据结构算法与实现的思路,其中包括影响公交数据结构算法与实现的因素,人性化的公交数据结构算法与实现,公交数据结构算法与实现的基本步骤。希望能对缓解城市交通压力问题提供一些借鉴。     

电动客车底盘车架结构设计要素分析

电动客车与传统内燃机驱动客车相比,在整备质量大小、能源提供形式、载荷分布、管线走向等多方面存在较大差异,对底盘的车架结构设计需要考虑使电动客车更加安全、节能、可靠的要求,在加工、制造工艺设计上符合电动客车底盘车架的更高的部件安装精度要求。     

潮州市公共交通线网组织优化研究

公共交通系统中各方面组织工作得以实施的基础,是线网的合理布局与优化,属于公共交通静态组织的范畴,在整个公共交通组织中它的作用是十分关键的。本文首先对公交线网组织优化进行简单的概述,接着对公交线网组织优化现状进行综述及针对性的评述,最后就潮州市公交交通线路组织中应注意的问题进行分析。通过文章的具体论述,希望对现实工作具有一定的指导意义。     

Environmental Accounting of Eco-innovations through Environmental Input–Output Analysis: The Case of Hydrogen and Fuel Cells Buses

The introduction of environmentally friendly innovations in both transport and energy sectors are included in the list of priorities of the European Union political agenda. This paper investigates the environmental consequences of the introduction of hydrogen and fuel cells technology in the European economic system by applying environmental input–output analysis and life cycle assessment tools. Hydrogen is produced through the reforming of natural gas and it is employed in fuel cells buses that offer transport services to final consumers. We have built three scenarios based on different assumptions on the final demand. We have shown the results for three impact categories: global warming, photochemical oxidation and acidification. The results suggest that the use of hydrogen in fuel cells buses is only environmentally desirable if accompanied either by the employment of renewable sources or by carbon dioxide capture, or both.     

Operational performance of U.S. public rail transit and implications for public policy

In today's tough economic environment, governments at all levels face significant budget shortfalls and public rail transit systems must compete with other public services for government subsidies. It is critical that public rail transit systems be concerned with their operational performance and efficient use of resources. In this paper, we develop a methodology that measures a rail transit system's performance relative to that of other rail transit systems, compares its performance to an appropriate efficient benchmark system, and identifies the sources of its inefficiency. We analyze the relationship between public subsidies and operational performance of public rail systems and show an inverse relationship between subsidization and efficiency.     

Does public transit reduce car travel externalities? Quasi-natural experiments' evidence from transit strikes

One of the unanswered questions in the field of urban economics is to which extent subsidies to public transit are justified. We examine one of the main benefits of public transit, a reduction in car congestion externalities, the so-called congestion relief benefit, using quasi-natural experimental data on citywide public transit strikes for Rotterdam, a city with mild congestion levels. On weekdays, a strike induces travel times to increase only marginally on the highway ring road (0.017 min/km) but substantially on inner city roads (0.224 min/km). During rush hour, the strike effect is much more pronounced. The congestion relief benefit of public transit is substantial, equivalent to about 80% of the public transit subsidy. We demonstrate that during weekends, travel time does not change noticeably due to strikes. Furthermore, we show that public transit strikes induce similar increases in number of cyclists as number of car travelers suggesting that bicycling-promoting policies to reduce car congestion externalities might be attractive in combination with first-best congestion pricing.     

Scheduling food bank collections and deliveries to ensure food safety and improve access

Food banks are privately-owned non-profit organizations responsible for the receipt, processing, storage, and distribution of food items to charitable agencies. These charitable agencies in turn distribute food to individuals at risk of hunger. Food banks receive donated food from national and local sources, such as The Emergency Food Assistance Program (TEFAP) and supermarkets. Local sources with frequent high-volume donations justify the use of food bank vehicles for collection. Food bank vehicles are also used to deliver food to rural charitable agencies that are located beyond a distance safe for perishable food to travel without spoilage. Due to limited funds, food banks can only afford to sparingly use their capital on non-food items. This requires exploring more cost effective food delivery and collection strategies. The goal of this paper is to develop transportation schedules that enable the food bank to both (i) collect food donations from local sources and (ii) to deliver food to charitable agencies. We identify satellite locations, called food delivery points (FDPs), where agencies can receive food deliveries. A set covering model is developed to determine the assignment of agencies to an FDP. Both vehicle capacity and food spoilage constraints are considered during assignment. Using the optimal assignment of agencies to FDPs, we identify a weekly transportation schedule that addresses collection and distribution of donated food and incorporates constraints related to food safety, operator workday, collection frequency, and fleet capacity.     

中小城市的公共交通问题及发展方略——以漳州市为例

伴随着城市化进程的不断推进,我国大量中小城市飞速发展,城市交通问题日益突出,从城市可持续发展的角度考虑,迫切需要大力发展公共交通。以漳州市为例,对我国中小城市公共交通发展过程中存在的公交出行需求、城市规划、政府支持力度和公交服务质量等方面的问题进行了研究,并就此提出了相应的解决对策。     

A study in using linear programming to design non-urban attendance areas

A great deal of recent work has been directed toward using mathematical programming to achieve racial balance in urban schools. However, with the ever increasing cost of fuel for buses, there also appears to be a need to apply these techniques in non-urban school districts to reduce the use of fuel. This paper describes the development of a linear programming model to assign students to schools in such a way, as to minimize student-miles. Using data gathered in a non-urban school district, this model was tested on a large scale linear programming package with encouraging results. The resulting computational results are presented and discussed along with comments on the additional work necessary to implement this model.     

城市公共交通满意度分析——以厦门岛为例

城市公共交通服务水平的提高对于促进城市交通可持续发展具有重要意义。公共交通满意度是乘客对于公共交通服务的一项直接反馈信息,反映了城市公共交通状况。在对厦门岛居民公共交通满意度大量数据调查的基础上,本文从住区尺度对居民的公共交通满意度进行了空间分析,然后结合受访居民聚类分析的结果,对厦门岛公共交通现状进行综合评价。评价结果表明:厦门岛整体公共交通满意度是可以接受的,但是满意度在空间分布上存在差异;公共交通中快速公交满意度高于普通公交;公共交通仍然在居民常用出行方式里面占有重要地位。最后找出存在的问题并提出优化的建议。     

Sim-heuristics low-carbon technologies’ selection framework for reducing costs and carbon emissions of heavy goods vehicles

ABSTRACT

UK logistics fleets face increasing competitive pressures due to volatile fuel prices and the small profit margins in the industry. By reducing fuel consumption, operational costs and carbon emissions can be reduced. While there are a number of technologies that can reduce fuel consumption, it is often difficult for logistics companies to identify which would be the most beneficial to adopt over the medium and long terms. With a myriad of possible technology combinations, optimising the vehicle specification for specific duty cycles requires a robust decision-making framework. This paper combines simulated truck and delivery routes with a metaheuristic evolutionary algorithm to select the optimal combination of low-carbon technologies that minimise the greenhouse gas emissions of long-haul heavy goods vehicles during their lifetime cost. The framework presented is applicable to other vehicles, including road haulage, waste collection fleets and buses by using tailored parameters in the heuristics model.     

渭南市朝阳天桥周边道路缓堵解决方案

针对渭南朝阳天桥周边在下班高峰期出现的严重交通拥堵和交通安全隐患问题,文中分析朝阳天桥周边具体公共设施设置和造成拥堵的实际原因,认为渭南市朝阳天桥道路拥堵的症结在于机动车和非机动车混行引起的路面暂时性拥堵。从城市规划的角度,建议应设置人行道护栏和重置公交站点,并结合土地利用现状,建议应在交通高峰期应该加大路口通行能力和人行道的利用率,用以解决非机动车非法侵占道路现象,考虑到交通的群体性特点,提出应在拥堵的高峰期加强管制力度。