长江江苏段船载危化品安全风险事故概率研究

长江江苏段危化品运输船舶日均流量达500艘次,年过境化学品运输量超过2亿吨,给沿江分布的集中式饮用水水源地带来巨大环境风险。本文将长江江苏段航道水域分成19段,结合统计的长江水路交通状况数据(AIS数据),利用统计学方法学和线性插值技术,对长江江苏段危化品船舶污染事故概率进行预测计算,以考察江段的安全环境风险承载力。针对长江江苏段危险品船舶的高风险,提出降低船舶安全事故概率的对策。     

基于GIS-AHP方法的危险品物流运输选线研究

文章针对地理信息系统（GIS）和层次分析法（AHP）在目标数据量化及综合评价方面的优点,提出了危险品运输选线GIS-AHP方法,阐述了GIS-AHP方法的具体实施步骤,并结合某跨地区危险品道路运输实例进行了选线分析。结果表明,该方法能显著提高危险品道路运输的风险综合评价水平,且所选路线科学、合理。     

欧洲危险品运输管理经验借鉴

如果单独考虑对生命和财产造成的伤害程度，在各种不同的运输方式中，因为公路往往通过人口密集的区域，所以依托公路的危险品运输较其他运输方式更为危险。加强危险品公路运输管理，对其风险进行评估，合理选择危险品公路运量等路径策略开始成为人们关注的焦点，欧洲在这方面积累了不少经验。     

危货运输经营：向左走？向右走？

随着国民经济建设步伐的加快，化工企业如雨后春笋般越来越多，生产的化工产品也越来越多，而绝大部分化工产品都属于危险品，都需要有危险货物运输资质的企业来运输。很多有商业头脑的经营者，都盯准了这块“大蛋糕”，虽然运输危险品存在高风险，但是有风险才有利润，风险越大，利润越高，     

居“危”思“安”,安全不容让步

正危险品安全监管的任何一个环节出问题,均可能成为下一个"炸弹"。"目前,全国取得危险品许可证的生产、经营和使用企业达28.5万余家。不少大容量储存设施陆续投用,运输线路也在变长,生产、储存,运输和物流环节的安全风险剧增。"3月3日,交通运输部安全总监成平带着《《关于如何改进危险品安全监管体制机制》的提案接受了     

基于公共安全三角形的危险品航空运输情景构建

针对危险品航空运输由于人员在运输环节中存在错误操作构成安全隐患的问题，基于公共安全三角形理论，构建危险品航空运输事件情景，提前为事故发生做出应急准备。首先，在危险品航空运输全流程风险分析的基础上识别并归纳运输流程中存在的致灾因子；同时，根据风险计算公式得到致灾因子的风险水平，经营人判断是否要进行情景构建。其次，将承灾载体按照人、物以及环境三大类进行划分。最后，根据承灾载体以及突发事件的具体情况结合其应急管理的需要进行情景构建，为危险品航空运输突发事件的应急管理提供指导。     

危货运输经营:向左走?向右走?

随着国民经济建设步伐的加快,化工企业如雨后春笋般越来越多,生产的化工产品也越来越多,而绝大部分化工产品都属于危险品,都需要有危险货物运输资质的企业来运输。很多有商业头脑的经营者,都盯准了这块"大蛋糕",虽然运输危险品存在高风险,但是有风险才有利润,风险越大,利润越高,为了丰厚的利润,部分经营者纷纷"试水",申办危险货物运输经营资质。根据《道路危险货物运输管理规定》(交通部2005     

开展危险品运输稽查活动应注意哪些问题

近日,嘉兴市公路运输管理处组织了一次危险品运输专项稽查活动,由于事前计划周全,组织严密,一举查获危险品黑车13辆,有效维护了危险品运输市场秩序。     

势在必行的全国危险品运输标准化建设

<正>标准数量少,远远满足不了危险品运输安全的需求。而运输急需的专项作业标准等尚未制定。为预防和减少危险品运输事故的发生,同时为运输企业和监管部门的实际工作提供指导,有必要制定和实施一系列相关的技术标准来约束和控制危险品运输全过程。现如今,我国危险品运输标准化建设情况如何呢?     

洋为中用加速标准化建设

为预防和减少危险品运输事故的发生．为了给运输企业和管理部门的实际工作提供技术指导，我国先后制定和实施了一系列相关的技术标准来约束和控制运输全过程，但相比国外，我国危险品运输标准化工作仍然存在不少问题：     

The role of attitude structures,direct experience and reframing for the success of congestion pricing

Congestion pricing was introduced in Stockholm in 2006, first as a trial followed by a referendum, and permanently from 2007. Public attitudes to the charges became more negative during the period from the decision to the start of the system. Once the trial started, public attitudes became dramatically more positive over the following years, going from 2/3 against the charges to more than 2/3 in favor of the charges. Self-reported changes in behavior and attitudes considerably underestimate actual changes: about 3/4 of the decrease in car trips and more than half of the change in attitudes seem to have gone unnoticed by respondents, ex post. Self-interest and belief in the charges’ effectiveness strongly affect attitudes at any given point in time, but can only explain a minor part of the change in attitudes. I suggest that the debate and the shift in attitudes can be understood as a public and political reframing of the congestion charges over time.     

新疆钢渣成渣工艺及集料化分析研究

本文通过对新疆不同成渣工艺及钢渣矿物化学组成、稳定性、物理指标进行分析,阐述了新疆钢渣技术现状,推动钢渣在公路工程中的资源化利用。新疆钢渣主要集中于北疆的乌昌地区,在热泼法和热闷法两种成渣工艺下,钢渣化学矿物成分相对稳定,属于高碱活性材料,并具有胶凝特性,同时具有一定工程级配。f-CaO含量热闷法小于热泼法,并且在自然环境下可陈化降解,有利于钢渣的稳定性。钢渣物理指标优于新疆常规碎、砾石材料,可集料化用于公路工程建设。此外,钢渣在工程应用中具有显著的经济和生态效益。     

Technical and environmental effects of biodiesel use in local public transport

Biodiesel use in local public transport could be especially significant in improving air quality in cities. The purpose of the experiments described in this paper was to evaluate the various (10, 20 and 50%) blends of biodiesel with diesel in the context of the engine and pollution aspects. As regards the experimental use of these findings on municipal buses, these experiments were the first reference in Hungary. The ages (15–20 years) and types of buses (Ikarus-280, Ikarus-260) used in the experiments are still common vehicles in Hungarian public transport. During our measurements, there was a significant difference between the change in fuel consumption of articulated and solo buses in traffic when compared to test bench measurements. The proportion of the engine performance reduction is nearly the same as that for biodiesel share in the blends. Most pollutants were decreasing (both at idle and full rpm), but this reduction is not directly proportional to the increase of the blending percentage. However, as for CO₂, emission increase was observed in the case of idle rpm in comparison to normal diesel operation, even though this phenomenon was not due to biodiesel use, but the catalytic converter and the fact that biodiesel was used for the first time in the engine concerned.     

Transport resilience and vulnerability: The role of connectivity

This paper aims to adopt a critical stance on the relevance and interpretation of the recently emerging concepts of resilience and vulnerability in transportation studies. It makes a clear distinction between engineering and ecological interpretations of these concepts and offers a systematic typology of various studies in this field. A core element in the study is the linkage between the aforementioned concepts and connectivity/accessibility in transport networks. The methodological findings in the study are put in perspective by addressing also such concepts as robustness, reliability and friability of transport systems.     

Urban walkability considering pedestrians’ perceptions of the built environment: a 10-year review and a case study in a medium-sized city in Latin America

ABSTRACT

Numerous methodologies measuring walkability have been developed over the last years. This paper reviews the Walkability Index (WI) literature of the last decade (2009–2018) and highlights some limitations in the current approaches. Only a few studies have evaluated walkability in Latin America, mainly in big cities but not in medium and small-sized cities in the region, which present their own urbanisation dynamics, security issues, sidewalk invasion problems, and poor planning. Furthermore, most WIs in the literature use objective mesoscale variables to assess walkability in a given area. This paper contributes to filling these gaps by generating new evidence from a medium-sized city in Latin America to question if characteristics of the built environment encourage walking trips, as found in the literature, are transferable among regions. The study also proposes a novel index comprised of microscale and mesoscale built environment variables to assess walkability using virtual tools and considering users’ perceptions. The WI estimation relies on ranking probability models. The results of the case study suggest that subjective Security and Traffic Safety are the most crucial factors influencing walkability in these kind of cities, which is different from what is found in the literature from cities in developed countries where Sidewalk Condition and Attractiveness are the most important factors. Security appeared to be strongly associated with a subjective dimension, represented by the fear of crime or perceived risk for crime, instead of the actual occurrence of crimes. This result evidences the importance of the physical attributes of the real world and how they are captured, judged, and processed by pedestrians. Then, regional transferability of WIs needs to be done carefully. Finally, results in this paper highlight the importance of microscale built environment characteristics in the WI formulation in these cities. Results are in line with other research in some cities of the region, which found that microscale variables such as pavement quality and presence of obstacles on the sidewalks are relevant components to promote walkability.     

频繁爆破下隧道内振动传播的数值研究

为揭示频繁爆破下隧道内振动传播衰减规律,文章以蒙华铁路段家坪隧道为工程背景,利用LS-DY NA建立了三维隧道模型,模拟分析了多次爆破下隧道内近区和中远区的振动传播规律。结果表明,质点垂向峰值振速随距离和爆破次数的增大而减小,少数振速有增大的现象;近区振动衰减较快,中远区振动衰减比近区缓慢;中远区a值比近区至少小12.5%,但整体上二者的a值随爆破作用次数的增加呈缓慢上升趋势;系数K随爆破作用次数的增加而降低,近区K值降低速率普遍大于中远区,且近区K值比中远区至少大29.1%;频繁爆破下,中远区比近区较符合萨道夫斯基经验公式。     

Productive efficiency and ownership of urban bus services

The established ownership mix of urban bus operations in Australia provides a unique opportunity to investigate the productivity differences between public and private bus service supply. Using duality theory in economics which links economic indices of factor productivity to the cost structure of a firm, we develop empirical measures of total and partial productivity of inputs, and adjust the differences for the effects of ownership status and operating environment. The evidence supports the notion that private supply of public passenger transport in general has performed more efficiently in the past than public supply, although the differences in productivity need not continue in the future.     

Driving behaviour at motorway ramps and weaving segments based on empirical trajectory data

In the vicinity of ramps, drivers make route choices, change lanes and in most cases also adjust their speeds. This can trigger anticipatory behaviour by the surrounding vehicles, which are also reflected in lane changes and/or changes in speed. This phenomenon is called turbulence and is widely recognised by the scientific literature and various design guidelines. However the knowledge about the characteristics of turbulence is limited. This study investigates the microscopic characteristics of driving behaviour around 14 different on-ramps (3), off-ramps (3) and weaving segments (8) in The Netherlands, based on unique empirical trajectory data collected from a video camera mounted underneath a hovering helicopter. The data analysis reveals that lane changes caused by merging and diverging vehicles create most turbulence, that an increase in the amount of traffic results in a higher level of turbulence and that an increase in the available length for merging and diverging results in a lower level of turbulence. The results of this study are useful for improving the road design guidelines and for modelling driving behaviour more realistically.     

Daily rhythms of suburban commuters’ movements in the Tallinn metropolitan area: Case study with mobile positioning data

The objective of this study is to analyse the diurnal rhythms of city life and its spatial differences in Tallinn, using mobile telephone positioning data. The positioning experiment was carried out in April 2006 over an 8-day period and 15-min intervals, with a random sample of 277 respondents living in new residential areas outside the city of Tallinn.The investigation of the space–time movements and daily distances of respondents showed that the majority of respondents had a similar temporal rhythm related to work, school, services and leisure in the city. Because of the different timing of those activities, the mobile positioning data made it possible to map functional differences in the city. The advantages and disadvantages of mobile positioning data in mapping urban life are discussed in the final section of the study.