道路交叉口冲突仿真分析

针对基于事故的安全评价在数量、周期、均值、随机性等方面以及基于现场冲突观测识别在主观性、可靠性、成本、指标全面性等方面存在的问题,提出基于冲突仿真的交叉口安全预评价分析方法:研究利用安全间接分析(SSAM)模型分析冲突的基本原理和冲突时间(TTC)、遭遇时间(PET)等分析指标的计算方法;以及利用VISSIM仿真软件进行冲突仿真分析应注意的策略。以邢台市某道路交叉口安全改善方案为例,进行改善前后冲突仿真的比较分析。研究结果表明,改善后在通行效率显著提升的同时,交叉、追尾、车道变换冲突的数量均显著减少,TTC值有所增加,说明改善后安全程度有所提升。笔者提出的方法和案例应用为道路交叉口改善措施的安全预评价提供了一种分析途径和有益借鉴。     

道路交通紧急救援服务点的优化选址

针对道路交通紧急救援对公平性、效率性、事故并发性的多目标决策需求,提出用于道路交通救援点选址的多目标决策模型。该模型通过最小化最大救援时间满足救援公平性;通过最大化一次覆盖的需求量和最小化救援点到需求点总加权时间满足救援效率;通过最大化备份覆盖的需求量满足事故并发与重大事故的救援。针对多目标决策模型,开发基于模拟退火法的优化解法,结合算例分析,能够获得减少最大救援时间、最大化一次覆盖和备份覆盖需求量的多个目标方向上最优解,实现pareto最优化的成功率均在95%以上。实例计算比较表明,笔者提出的模型与算法可以为决策者提供多目标选址方案。     

摩托车头盔与摩托车交通事故的相关研究

我国近年来的摩托车死亡事故占交通事故死亡总数的25％-28％。在我国摩托车使用比较普及的地区,摩托车交通事故数占到该地区交通事故总数的70％-80％,伤亡比例占到总数的50％以上,甚至更高。通过对摩托车交通事故伤亡人员的具体受伤部位分析,发现头部受伤致死的比例非常高,占到该类事故死亡总数75％以上,远远高于其他部位受伤致死率。摩托车驾乘人员头部受伤致死的主要原因是摩托车驾驶乘人员头盔佩戴率低和佩戴的头盔质量差,对头部未能起到应有的保护作用。造成这一局面既有摩托车乘员头盔标准等技术层面存在的问题,又有行业监管等政策层面存在的问题,最后,文章从摩托车头盔标准方面提出了几点修订建议,为规范头盔行业进行基础性的准备。     

基于仿真的高速公路紧急事件交通流特征研究

研究高速公路紧急事件下的交通流特征,对于减少高速公路拥挤、降低二次事故、提高通行能力有重要的作用。由于高速公路紧急事件具有偶然性、不可预测性的特点,在实际调研中往往难以及时捕捉到交通事件的相应信息,导致源数据不足进而影响研究的进行。本文通过微观仿真手段,结合实地调研获得紧急状态下车辆运行参数,在AIMSUN仿真环境下加载紧急事件,建立了高速公路微观路段的仿真模型。并将路段平均车速、密度、最大排队长度等作为指标,定昔计算紧急事件下各种交通参数的变化规律。最后与调研结果进行了对比,表明仿真结果与实际情况较为一致。     

"九五"期间乌鲁木齐市交通噪声的控制措施及效果

在分析交通噪声影响因素的基础上,对乌鲁木齐市近十年控制交通噪声污染的措施和效果进行了探讨。     

Migratory crustaceans as biomonitors of metal pollution in their nursery areas. The Lesina lagoon (SE Italy) as a case study

Lichens collected in an unpolluted forest (background) in November 2004, transplanted at 41 sampling sites along the Madina-Tetteh Quarshie road, retrieved in February 2005 and analysed were found to contain higher concentrations of Manganese (Mn), Vanadium (V), lead, Cadmium (Cd), Chromium (Cr) and Nickel (Ni) than in the background area. Observations showed that of all the heavy metals studied, Manganese concentrations were highest at all sampling points with maximum values around a traffic light, an intersection and car fitting/mechanic workshops. Significant correlations were found between Ni and Mn, Mn and Cr and Mn and V. Statistical analysis also revealed a relatively even dispersion of the studied elements on the eastern side of the road than on the western side.     

Air Quality Monitoring and Management in Lisbon

The environmental decision-making process is related with the interpretation of data both in spatial and temporal dimensions. This paper presents a methodology that integrates the time-space framework of air quality data to infer the temporal pattern and spatial variability that could be interpreted for environmental decision purposes. Variograms that accommodate time and space lags were used for the analysis and proved to be effective. Its environmental meaning, in particular its relationship with traffic patterns is discussed. Data from air quality monitoring stations located in the central part of Lisbon were used in this study. It describes a strategy to identify the type of vehicles responsible for certain pollutant levels, particularly for nitrogen oxides, and discusses the application of new air quality European legislation to the city of Lisbon, Portugal.     

南京市城市典型道路交通噪声控制措施效果初探

针对南京市典型道路的交通噪声控制措施,分别选取低噪声路面、声屏障、隔声窗3种噪声控制措施进行监测,监测显示低噪声路面对整体声级降噪有限,声屏障对于1kHz倍频带以上的中高频隔声相对较好,真空玻璃隔声窗能对低频噪声有显著改善。     

云南山区公路事故多发路段安全对策措施研究

分析云南山区公路严峻的交通形势,及山区公路交通事故的特征、事故形态及影响因素,研究山区公路交通事故发生的机理。从人、车、路和环境等方面分析事故产生的原因,提出针对云南山区事故多发路段安全对策措施。分析表明,在云南山区,路况、人员安全素质、车辆性能、安全管理均处于较低水平,是重大事故多发的根本原因。提高系统安全性,实现系统功能最强,应使系统各要素相互匹配,以实现本质安全。     

Effects of Road Networks on Bird Populations

Abstract: One potential contributor to the worldwide decline of bird populations is the increasing prevalence of roads, which have several negative effects on birds and other vertebrates. We synthesized the results of studies and reviews that explore the effects of roads on birds with an emphasis on paved roads. The well‐known direct effects of roads on birds include habitat loss and fragmentation, vehicle‐caused mortality, pollution, and poisoning. Nevertheless, indirect effects may exert a greater influence on bird populations. These effects include noise, artificial light, barriers to movement, and edges associated with roads. Moreover, indirect and direct effects may act synergistically to cause decreases in population density and species richness. Of the many effects of roads, it appears that road mortality and traffic noise may have the most substantial effects on birds relative to other effects and taxonomic groups. Potential measures for mitigating the detrimental effects of roads include noise‐reduction strategies and changes to roadway lighting and vegetation and traffic flow. Road networks and traffic volumes are projected to increase in many countries around the world. Increasing habitat loss and fragmentation and predicted species distribution shifts due to climate change are likely to compound the overall effects of roads on birds.