浅谈施工技术方案优化效益——路基防护工程

成本管理是项目投资管理重要组成部分和主要工作任务之一。本文以阆中马啸溪嘉陵江大桥引道路基坡面由硬型改为边坡生态防护的施工技术方案优化为例,说明施工技术方案优化在项目投资管理中将产生较好的经济、社会效益。     

道路设计中生态化设计的运用分析

为有效提高道路设计的生态效益,对道路设计中生态化设计的运用进行分析。首先,阐述道路设计中生态化设计的定义与生态化设计应遵循的原则;其次,分析道路设计中应用生态化设计的必要性;再次,对道路设计中生态化设计的主要内容进行说明,总结道路设计中生态化设计要点;最后,提出推动道路设计中生态化设计应用的对策,包括完善相关法规、加大技术研发和示范力度、积累推广生态化技术应用经验等,以期为道路设计相关工作提供参考。     

铁路在综合交通运输体系的比较优势和新任务

从技术经济、节能环保、土地占用、经济安全等方面对铁路在综合交通运输体系中的比较优势进行了分析,总结了新形势下铁路面临的新任务。结果表明,按单位里程完成的货物周转量分析,铁路约为水运的0.5~0.8倍,公路的20~35倍,民航的4500~6500倍。按完成单位货物周转量的运输费用分析,水运、公路、民航分别约为铁路的1/2、10倍、20倍。铁路单位里程造价一般高于公路,但完成单位客货运量建设成本基本相当。铁路运输节约能源明显,水运、公路、民航分别约为铁路内燃机车万吨公里能耗的2.5倍、20~35倍、125倍。铁路和水运属于清洁型运输方式,公路和民航有害气体排放强度分别约为铁路的5倍和30倍。按单位运输能力计算,I级双线铁路占地是一级公路、四车道高速公路、六车道高速公路的16%、33%、43%。铁路运输安全性远远高于公路,与水运相差不大。新形势下铁路发展的新任务主要有:发挥铁路支撑引领作用;加强铁路供给侧改革;发挥铁路优势新潜力。     

高寒高海拔地区路域生态修复技术体系研究

路域生态修复技术是降低公路建设环境影响的重要手段。由于高寒高海拔地区的地质环境与植物生长条件差异,导致现有的技术体系无法满足该地区生态修复工程的实施。本文从高寒高海拔地区的环境特点出发,结合工程经验,建立了适应于高寒高海拔地区的生态修复技术筛选体系与物种配置方案,形成了完整的高寒高海拔地区生态修复技术体系,对该地区路域生态修复的实施具有指导意义。     

城乡公交站场设施管养机制初探

事实证明,与农村道路建设配套的城乡公交站场基础设施,已经在政府部门的大力推动和农村发展的迫切需求下得到了快速有效的扩张。但是,在城乡公交站场设施飞速发展的背后,却往往由于对其管理不善、维护不当等因素,使之不能发挥正常的站场功能和作用。本文作者结合本职工作,在深入实际调研的基础上,就如何加强城乡公交站场设施的管理、养护工作,建立长效的城乡公交站场设施管养机制进行了分析研究,希望与各位同行一起探讨     

构建黄浦江水上巴士客运系统

即将在黄浦江两岸召开的2010年上海世博会将有力推动浦江沿岸新一轮的规划和建设,以此为契机,黄浦江水上客运系统的规划工作亦应积极的融入其中。水上巴士作为一种水上交通手段,在交通空间上具有人性化、捷运化、生态化的特点,并能提供畅达、舒适、清洁的交通服务,因此常常为城市水域旅游交通所青睐。本文在分析浦江沿岸交通现状的基础上,阐释了构建黄浦江水上巴士客运系统的观点,并提出相应的规划方案及设施建设意见,以保障其“客运通道 游憩走廊”功能的实现。一、黄浦江水上客运现状1、黄浦江现有的水上客运服务沿黄浦江现有18个轮渡站点…     

加强前期工作 科学有序投资

<正> 建设项目的前期工作是整个项目建设周期中的一个重要环节,也是投资计划管理的一项重要工作。它主要包括项目的酝酿、调查、可行性研究和论证、可研报告的审批、初步设计等阶段。它是指在项目投资决策前,对项目有关的社会、经济和技术等各方面的情况进行深入细致的调查研究;对各种可能拟定的建设方案和技术方案进行全面的技术经济分析和比较论证,并对项目建成后的经济效益和社会效益进行科学的预测和评价。在此基础上,综合研究建设项目的技术先进性和适用性、经济合理性和有利性以及建设的可能性和可行性,由此确定该项     

推进生态文明建设引领交通转型升级——《推进交通运输生态文明建设实施方案》解读

<正>4月5日,交通运输部印发《推进交通运输生态文明建设实施方案》(简称《方案》),阐述了交通运输生态文明建设的总体要求、目标及基本原则,从优化交通运输结构、加强生态保护和污染综合防治、推进资源节约循环利用、强化生态文明综合治理能力四个方面提出了推进交通运输生态文明建设的15项重点任务,并制定了强化组织领导、多渠道筹措资金、加强宣传教育3项保障措施。《方案》是交通运输行业贯彻落实党中央、国务院生态文明建设     

生态化建设理念的公路设计方法

"要想富,先修路",这句口号深入人心,作为一个地区经济社会发展的必要条件,公路建设是必然的。然而在公路建设的过程中容易造成植被破坏、水土流失等问题,在后期的使用过程中也会对周边环境产生多方面的影响,因此,在这种情况下,生态化公路应运而生。本文旨在以生态化建设理念为立足点,在对"生态化理念"进行透彻分析的基础上,探索基于生态化建设理念下的公路设计方法。     

基于乘客健康视角的公交站优化设计与管理

现有的公交站设计与管理没有从出行者健康视角来考虑,造成出行者健康存在隐患。本文设计了四组对比试验,运用多元回归模型分析环境影响因子、交通影响因子、车站因子和天气因子对公交车站PM2.5浓度的影响。结果表明,半封闭公交站开口朝向,距交叉口距离,是否在建筑峡谷,小车流量,大车流量,气温,风速对公交车站PM2.5浓度有显著影响,其中建筑物峡谷与大车流量对公交车站PM2.5浓度影响最为明显。基于分析结果,本文提出基于乘客健康视角的优化措施,包括公交车站布局位置、公交车站开放形式、扩大站点容量减少怠速行驶、公交车站进站停车管理和公交车能源升级。     

基于港口枢纽处TOD公交站点选址模型的设计

本文针对中小型沿海城市提出的成本模型嵌入到公交站点优化方案中,构建各项成本的表达式,整合并建立以成本最小为目标的公交站点选址模型,对TOD公交站点的选址进行合理规划。此模型可有效运用到在中小型沿海城市中港口枢纽处的公交站点合理设置中,即实现乘客从轮渡到公交的零换乘,又能使港口枢纽对港口枢纽出入口与城市道路交汇处的交通现状影响达到最小,公交的通行能力达到最高。     

Optimal bus fleet management strategy for emissions reduction

Transportation is a major cause for environmental degradation via exhaust emissions. For many transit-oriented metropolitan areas, bus trips often constitute a sizeable mode share. Managing the bus fleet, in particular updating buses to comply with the newer emissions standards, therefore, can have a substantial impact on transportation-induced air quality. This paper presents the approach of remaining life additional benefit–cost (RLABC) analysis for maximising the total net benefit by either early-retiring or retrofitting the current bus fleet within their lifespans. By referring to the net benefits for different bus types estimated by RLABC analysis, the most beneficial management scheme for the current bus fleet can be identified. Optimal bus fleet management (BFM) models based on the RLABC analysis for the operator and the government are developed. Then a government subsidy plan is produced to achieve win–win solutions, which will offer efficient and flexible management schemes. To illustrate the approach, the largest bus company in Hong Kong, which carries more than 23% of the total trips in Hong Kong, is taken as a case study example. Instead of adopting a fixed retirement plan, such as replacing buses at the age of 17 as is currently practised, the proposed method develops an optimal BFM scheme that progressively phases out buses or retrofits them. This study produces promising results to demonstrate the large benefit of this approach for optimal bus fleet management.     

Railway planning in developing countries: a case study of Colombia

This paper describes a study of possible network changes for the Colombian railway system. A cost model is developed and the variation of costs with traffic density and with gradient is analysed and found to be different from that expected from experience in developed countries. The evaluation of network changes is carried out by a form of systems analysis in which two new lines and many closures are examined. Closures are evaluated by means of social cost benefit analysis incorporating a consumers’ surplus approach. The study recommends fairly radical changes to the present network configuration, these involving the construction of one new line and the closure of several existing ones.     

快速公交系统站台停靠时间模型研究

快速公交系统停靠站台停车延误是影响快速公交运行车速的关键因素之一,因此构建快速公交系统站台停靠时间模型是提升快速公交服务水平的基础理论研究。本文选取盐城BRT-1号线的起始站、中途站、客流离散站等三类站点为研究对象,综合运用数理统计法与数据挖掘法,构建快速公交系统站台停靠时间模型,并对该模型的合理性进行了检验。研究表明:盐城市BRT-1号线三类站台的快速公交车辆停靠时间与上下车乘客人数呈线性关系,即快速公交车辆停靠时间与上下车乘客人数的检验参数R2均大于0.8。     

On including travel time reliability of road traffic in appraisal

In many countries, decision-making on proposals for national or regional infrastructure projects in passenger and freight transport includes carrying out a cost–benefit analysis for these projects. Reductions in travel times are usually a key benefit. However, if a project also reduces the variability of travel time, travellers, freight operators and shippers will enjoy additional benefits, the ‘reliability benefits’. Until now, these benefits are usually not included in the cost–benefit analysis. To include reliability of travel or transport time in the cost–benefit analysis of infrastructure projects not only monetary values of reliability, but also reliability forecasting models are needed. As a result of an extensive feasibility study carried out for the German Federal Ministry of Transport, Building and Urban Development this paper aims to provide a literature overview and outcomes of an expert panel on how best to calculate and monetise reliability benefits, synthesised into recommendations for implementing travel time reliability into existing transport models in the short, medium, and long term. The paper focuses on road transport, which has also been the topic for most of the available literature on modelling and valuing transport time reliability.     

Incentive subsidy scheme design with elastic transport demand

Huge public transport subsidies caused by deficits have become a heavy financial burden on some local governments due to the decline of bus passenger numbers. It is essential to apply the performance‐based contract to bus services considering maximization of social welfare. This paper constructs an incentive subsidy contract considering the decision‐making powers of the service level and calculating the proper frequency elasticity aiming at two problems of performance‐based contracts. Meanwhile, we consider a role of bus operators ignored by most researchers. Under the scheme, the decision‐making power of the service level is discussed based on five assumptions, and meanwhile, bus operators are motivated to reduce cost and improve service level in the scheme. The case of the bus service of Arao city indicates that the optimal frequency equals to zero when bus operators decide frequency. If bus operators determine efforts, the optimal effort also equals to zero with the goal of maximizing the profit. Also, bus operators can play their roles in lessening cost and improving service level to help bus operators and the local government achieve a win‐win situation, which maximizes the social benefit in this subsidy scheme when all factors are decided by the government. Copyright © 2013 John Wiley & Sons, Ltd.     

贵州、广东两省农村客运站的建设及启示

文章介绍了贵州、广东两省农村客运站建设情况,指出农村客运站建设面临的困难和问题,总结两省农村客运站建设的经验,提出了加快农村客运站建设和管理的措施及建议。     

Enhanced bus operations: The Curitiba model and its applicability to China

Buses will remain the backbone of public transport systems for some time to come because of their lower cost and higher flexibility in relation to rail transport. However, buses are perceived as being an inferior mode of public transport and do not offer as much carrying capacity as rail transport. Following the Curitiba model, this paper looks at the potential for transferring some of the key advantages of rail transport to bus operations. This involves transforming bus stops into enclosed stations, with ticket purchase and/or checking in the station and at‐grade access to vehicles. It also involves the extensive use of bus lanes. The potential contribution of transport telematics is looked at, in particular the use of smartcards for payment in a closed fare system. The potential role of the Curitiba model for China is assessed in the context of toll road construction.     

Joint optimization of a rail transit line and its feeder bus system

A model is developed for jointly optimizing the characteristics of a rail transit route and its associated feeder bus routes in an urban corridor. The corridor demand characteristics are specified with irregular discrete distributions which can realistically represent geographic variations. The total cost (supplier plus user cost) of the integrated bus and rail network is minimized with an efficient iterative method that successively substitutes variable values obtained through classical analytic optimization. The optimized variables include rail line length, rail station spacings, bus headways, bus stop spacings, and bus route spacing. Computer programs are designed for optimization and sensitivity analysis. The sensitivity of the transit service characteristics to various travel time and cost parameters is discussed. Numerical examples are presented for integrated transit systems in which the rail and bus schedules may be coordinated.     

西江黄金水道建设的生态环境问题及对策研究

文章基于西江黄金水道的生态环境现状和建设规划情况,分析了在西江开发建设过程中产生的主要生态环境问题,并提出了针对性的保护对策,为协调西江开发建设与生态环境保护的关系提供理论依据。