Measuring the Cost Effectiveness of Multimode Bus Transit in the Presence of Accident Risks

Abstract

This study employs the directional graph distance function and the multiactivity data envelopment analysis (DEA) approach, which incorporates both desirable and undesirable outputs, in order to provide a more complete representation of the multimode bus production technology from which environmentally and risk-sensitive cost effectiveness measures can be generated. We treat accident cost as the risky output in the sense that we wish to increase desirable outputs and decrease risky output and inputs. The approach is applied to the problem of measuring the cost effectiveness of 24 bus companies in Taiwan. An empirical illustration suggests that the overall cost effectiveness rankings turn out to be very sensitive to whether or not the graph multiactivity DEA approach is adopted. This implies that the conventional DEA cost effectiveness measure may be seriously misleading if it ignores the cost effectiveness of organizations that carry out various activities whilst sharing common resources.     

Accident cost saving and highway attributes

Two semi-logarithmic regression models are developed to estimate accident rates and accident costs, respectively, for rural non-interstate highways in the state of Iowa. Data on 21,224 accidents occurring between 1989 and 1991 on 17,767 road segments are used in the analysis. Seven road attributes of these road segments are included as predictor variables. Applying the resulting regression models to a rather typical highway upgrade situation, the present value of the accident cost saving is computed. The sensitivity of the estimated cost saving to values for fatal, personal injury, and property damage only accidents is tested.Because factors other than road characteristics greatly influence accident costs, the models developed in this research explain a limited amount of the variance in these costs among road segments. Results of the analysis indicate that the most important attribute associated with accident costs is average daily traffic per lane, followed by conditions requiring passing restrictions and the sharpness of curves. Varying the values for the three categories of accidents shows that results are far more sensitive to the value of personal injuries than fatalities. The feasibility of using predictive models of accident costs in benefit-cost analyses of highway investments is demonstrated.     

Partial productivity measures and total factor productivity in the air transport industry: Limitations and uses

In recent years the measurement of productivity has increasingly focused on measuring total factor productivity or TFP. Additional research has investigated the reasons for differences in TFP between firms. The implicit assumption behind this work is that simpler measures of industry productivity (such as revenue ton-miles per employee) can seriously misstate both the level and growth rate of productivity. As a result, accurate analysis of productivity requires information on TFP. While this argument is not open to debate on a theoretical basis, the extent that simple measures of productivity inaccurately portray TFP has not been investigated in anything but a cursory manner. This paper investigates the relationship between typical industry measures of productivity and TFP using a data set of U.S. and non-U.S. airlines for the period 1970–1983. The paper examines both levels of productivity and growth rates. The results indicate the extent to which industry measures accurately or inaccurately reflect the more comprehensive measure of productivity (TFP). To the extent that industry measures are inaccurate, this paper investigates the possible sources of error in order to determine if slightly altered industry measures might more accurately reflect TFP.     

并行管道风险因素与事故交互作用分析

随着能源需求的不断增加,国内管道建设处在一个新的高潮时期,受各种因素制约,近距离并行敷设管道越来越多,给管道的建设和运行安全带来了新的挑战。通过分析并行管道设计、建设和运行阶段所面临的风险因素以及现有研究状况,并着重对管道运行阶段事故交互影响的失效概率进行了讨论。最后提出,对于并行管道的安全问题,不仅要考虑失效后果的严重程度,也应考虑管道发生事故后产生交互影响的概率问题,有效降低管道失效概率是解决并行管道安全问题的主要途径。     

输油管道泄漏事故分析及处理

输油管道出现泄漏事故时,可以通过首站的压力检测系统记录的数据进行分析.首站外输排量发生变化、末站更换罐以及管道泄漏时的压力波分别具有不同的特征.根据这些压力波,可以准确判断出管道泄漏的工况.管道上连接低压阀门损坏出现的泄漏事故原因,可以根据现场实际情况进行准确地分析.管道泄漏的事故处理必须有严密的施工组织,充分的准备,对泄漏处进行及时抢修,才能保证输油管道的安全运行.     

客车翻车事故的原因剖析与防范举措建议

本文结合交通事故发生的人、车、路及环境等因素,分析了近三年来重特大客车翻车事故,并梳理了客车翻车的主、客观原因。在此基础上,对客车技术现状和客车运行状态时的受力进行分析,为减少客车翻车事故提出了相应防范措施。     

货车侧翻事故分析及影响因素研究

货车侧翻事故是重要的交通安全问题之一,通常会造成周围其他小型车辆的严重人员伤亡.为减少侧翻事故的发生,分析货车侧翻过程,根据货车侧翻时的运动状态,将其侧翻类型划分为静态侧翻、转向侧翻和碰撞侧翻三种类型,并分别建立了相应的动力学模型对侧翻过程进行运动分析,提出了侧倾期、侧翻上升期和侧翻下落期三个时期划分事故过程,并给出了各时期间的运动特性及临界转换条件;最后,着重分析了货车装载质量和行驶速度对侧翻发生的影响.研究结果表明:侧翻角速度、侧翻角和横向载荷转移率可分别作为评定货车处于不同横向运动状态时期是否会发生侧翻的合理指标;货车装载质量和行驶速度均与货车侧翻风险呈正相关关系.     

交通事故与公路运输业状况的关联分析

文章针对交通事故与公路运输业状况,结合我国1998-2006年间的交通事故与公路运输业典型指标的统计数据,采用灰色关联分析法对交通事故及公路运输业状况之间的关联度进行了研究,可为政府相关部门加强交通安全管理、抑制交通事故的发生提供一定的科学依据。     

新时期城市综合交通体系规划的挑战和应对思考

当前我国社会经济发展已迈入新的转型时期,经济新常态、新型城镇化、互联网+等新理念逐步冲击着传统各个行业,相应的对城市综合交通体系规划也提出若干挑战。从规划整体技术流程与具体内容模块两方面入手,以理念、措施和实例,探讨新时期城市综合交通规划对当前挑战的应对,并提出综合交通体系规划应大胆创新,与时俱进,在对自身进行"瘦身"的同时,由体系规划向规划体系转变。     

盾构隧道下穿铁路工程风险及对策

结合杭州地铁一号线下穿铁路艮山门辅助编组站盾构隧道工程,对其可能出现的风险进行了研究分析,提出了相应对策,并对盾构下穿施工参数提出了建议;针对可能出现的轨道过大变形,提出了对盾构穿越区采用分块加固的措施,并对加固后的效果进行了分析。     

河口大跨桥梁交通事故特征研究——以上海长江隧桥为例

河口大跨桥梁作为连接沿海地区各中心城市的重要运输通道,对减少公路运输里程、加强区域合作交流、缓解湾区城市拥堵以及促进区域经济发展起到了极大的推动作用。但近年来河口区域大跨桥梁处交通事故频繁发生,造成较大的人员伤亡和财产损失,带来不良的社会影响。选取上海长江隧桥作为研究对象,采用描述性统计、交叉表分析等方法,从小时分布、星期分布、季节分布以及空间分布等方面对河口区域大跨桥梁的交通事故特征进行归纳总结,结果表明河口区域大跨桥梁在主桥附近区域以及出口区域事故率较高,且事故高发时段分布在白天8时至14时。     

Automated tuning of ITS management and control systems: Results from real-life experiments

The design and deployment of the majority of Management and Control Systems (MCS) for ITS involves a tedious, effort- and time-consuming manual tuning and calibration procedure not only during the initial design and deployment of the ITS but, in most cases, during its whole lifetime. Recently, we have developed and evaluated, both by means of theoretical analysis and extensive simulation experiments, a new methodology which fully automatically takes over the manual tuning and calibration procedure. Most importantly, this new methodology, called Adaptive Fine-Tuning (AFT), achieves to improve the performance of the system and compensate the effect of the continuous changes of its behavior that may be due to either internal or external factors. In this paper, we report results of implementing AFT to a real-life ITS MCS. More precisely, this paper reports and analyzes the results from implementing AFT to an urban traffic signal control application. The results from AFT real-life application demonstrate that it is capable of significantly improving the performance of the system in a safe and robust manner. Moreover, the real-life results exhibit the capability of AFT to efficiently adapt and compensate in cases of changes in the system behavior, even if these changes are significant.     

山区二级公路交通事故特征及影响因素分析

文章以重庆南(岸)涪(陵)二级公路为例,基于道路交通事故统计数据,从交通事故形态分布、事故交通方式分布、事故时间分布等方面系统分析了该路交通事故的特征,并探讨了驾驶人及行人、车辆因素和道路条件对道路交通事故的影响.     

浙江省高速公路交通事故特点及防治措施研究

随着经济的快速发展,高速公路通车里程得到快速增长,道路客、货运量及周转量不断高速发展,但高速公路的交通安全问题已经成为一个重要的研究课题。本文首先分析了浙江省高速公路交通事故的特点,然后运用轨迹交叉论进行交通事故的原因分析,识别浙江省高速公路危险源,最后有针对性地提出了浙江省高速公路交通事故防治措施。     

铁路改革发展的风险、挑战与对策研究

加快铁路发展受制于债务、经营、资产与稳定四大风险,深化铁路改革将面临铁路的国家所有权政策、网运关系、现代企业制度、混合所有制、投融资体制、债务处置、公益性补偿、企业运行机制、改革目标与路径、改革保障机制、监管体制等诸多挑战。为此,本文提出正确认识深化铁路改革时机、尽快启动铁路改革顶层设计、适时启动中国铁路总公司(下称铁总)企业改制、指导铁总完善企业治理结构、引导铁总优化资本结构、督促铁总深化其他改革等六个方面的若干对策,以供参考。     

Combining Intermodal Transport With Electric Vehicles: Towards More Sustainable Solutions

Abstract

This paper analyses the feasibility of incorporating electric or hybrid vehicles in intermodal transport for the transportation of containers in the pre- and post haulage (PPH) operation. In Europe, the intermodal transport market is being strongly supported, as it is seen as one of the keystones of a sustainable mobility system policy. The introduction of environmentally friendly electric/hybrid vehicles for the pre- and post haulage operation would mean a further enhancement leading to a more complete ecological intermodal transport chain. PPH operations are usually no longer than 30 km, and, hence, could possibly be handled by electric or hybrid vehicles.

Hybrid electric vehicles (HEV) combine electric and other drive systems, such as internal combustion engines, gas turbines and fuel cells. Hybrid electric vehicles merge the zero pollution and high efficiency benefits of electric traction with the high fuel energy density benefits of an energy source or thermal engine. The use of electrically driven vehicles for goods distribution has already been successfully proven in international demonstration projects, such as ELCIDIS. Transport of intermodal units (such as ISO containers), however, requires electric/hybrid heavy-duty goods vehicles, which are not readily available on the market, but for which the technology exists.

Different possibilities are assessed as to their technical, financial, organizational and environmental feasibility and suitability. This analysis is based on a typical mission for pre-and post haulage operations, such as type of trips, distance, frequency, urban/suburban, etc.     

基于事故分类的道路车辆模块化清障救援方案研究

参照交通运输行业标准《道路车辆清障救援操作规范》(JT/T 891-2014),本文归纳提出了牵拉、起吊、扶正、拖运四类基本操作和以事故形态为基础的道路交通事故分类方法。在操作分解与事故分类基础上融入模块化思想,创造性的提出基于事故分类的模块化救援方案,通过四类基本操作的组合,实现碰撞、碾压、翻车、坠车、落水、烧毁、货物散落、抛锚等八类不同形态的事故车辆的针对性清障救援实施处置方案。     

Impact of ITS measures on public transport: A Case study

Intelligent Transport Systems (ITS) have a wide range of applications. They range from the more traditional signal coordination system to concepts such as smart cars and smart roads. This paper describes transit‐based ITS measures in Singapore. The island‐state has plans to double the current 90 km rail network over the next ten years and has also implemented or committed to implement many ITS initiatives that impact upon the public transport systems. The aim of these investments is to achieve a high transit modal share using a comprehensive transit network. ITS measures that can promote this aim include: automatic vehicle location systems for buses and taxis, integrated transit fare systems using contactless smart cards, rail information systems, multi‐modal travel guides on Internet and electronic road pricing. The potential impacts of these measures are delay reduction, more comfort, productivity gain and better network accessibility. ITS measures do not necessarily add physical capacity to a public transport system but are excellent supporting measures to encourage the modal shift to transit, particularly if a quality transit system is already in place.