公路隧道运营期风险定量分析模型研究

文章借鉴风险评估理论,建立了一套适用于公路隧道运营期风险分析的定量风险分析模型,对隧道事故场景、发生概率、后果等进行评估。同时建立了事故疏散模型和FED人员逃生条件模型,为公路隧道运营期风险分析提供了方法依据。     

Economic appraisal of universal design in transport: Experiences from Norway

Economic assessment of universally designed transport projects has not been studied in depth in the transport planning literature. Universal Design (UD) refers to the design of transport systems in a way that they are accessible to all users, irrespective of the users’ abilities. This definition of UD has not yet gained roots in the transport economic literature. The conventional thinking is that UD is for the few, i.e., the impaired, and given that they are few in numbers, UD projects will generally be unprofitable from a socioeconomic point of view because benefits will be low while investment costs will be too high. The objective of this paper is to prove the opposite: UD projects benefit all users of the facility, whether impaired or not, and the additional costs of implementing them are generally low; hence, their net present values are high and positive. We build on collaborative work between the Norwegian Public Roads Administration (NPRA) and the Institute of Transport Economics (TOI) aimed at creating guidelines for assessing the economic merits of UD projects. Therefore, in this paper, we: (1) define how UD is to be understood in the context of road and public transport; (2) describe the types of benefits and costs that accrue to users if UD projects are implemented; (3) address how the benefits and cost can be valued in monetary terms; and (4) using three different types of projects, demonstrate that UD projects are surprisingly profitable from a socioeconomic point of view. Finally, we address the implications of our findings and explain why governments need to be concerned with UD of transport systems.     

A contribution to environmentally friendly winter road maintenance: Optimizing road de-icing

This article deals with the specific road phenomenon in winter, when driving conditions suddenly become significantly worse, although the global weather conditions have not significantly altered. Recognizing and adjusting to such fast changing conditions has been one of the most difficult and demanding tasks for the winter road maintenance services. Nevertheless, it is known that some events can be predicted. The road temperature pattern is studied formally in terms of the road temperature function, thus enabling predictions about the temperature range on different road sections. It is claimed that the road temperature pattern is predictable when only a very small number of carefully chosen measuring spots are taken into account. Furthermore, the methodology of defining temperature measuring locations is described.     

Modelling the effects of road pricing on traffic using ERP traffic data

Singapore’s Electronic Road Pricing (ERP) system involves time-variable charges which are intended to spread the morning traffic peak. The charges are revised every three months and thus induce regular motorists to re-think their travel decisions. ERP traffic data, captured by the system, provides a valuable source of information for studying motorists’ travel behaviour. This paper proposes a new modelling methodology for using these data to forecast short-term impacts of rate adjustment on peak period traffic volumes. Separate models are developed for different categories of vehicles which are segmented according to their demand elasticity with respect to road pricing. A method is proposed for estimating the maximum likelihood value of preferred arrival time (PAT) for each vehicle’s arrivals at a particular ERP gantry under different charging conditions. Iterative procedures are used in both model calibration and application. The proposed approach was tested using traffic datasets recorded in 2003 at a gantry located on Singapore’s Central Expressway (CTE). The model calibration and validation show satisfactory results.     

橡胶混凝土物理力学性能研究

为研究橡胶颗粒对普通混凝土性能的变化趋势,论文分析了不同橡胶颗粒掺量的混凝土路用性能．通过密度、抗折强度、抗压强度及劈裂强度试验,研究掺橡胶颗粒的混凝土基本力学性能及物性的变化规律;采用噪声仪研究了橡胶混凝土的减振降噪效果．研究结果表明：随着橡胶颗粒掺量的增加,橡胶混凝土的密度、抗折、抗压及劈裂强度、压折比及噪声水平逐...     

国产环氧沥青混凝土钢桥面铺装施工适用性研究

为提高国产环氧沥青混凝土在钢桥面铺装中的施工质量,本文对其施工性能进行研究。通过室内沥青混合料马歇尔试验及沥青粘度试验,对国产环氧沥青混凝土与美国环氧沥青混凝土的常温养护、模拟夏季养护马歇尔稳定度及沥青粘度等性能进行比较,提出了国产环氧沥青混凝土钢桥面铺装施工季节、养护时间等方面的建议。     

对于哈尔滨市地区道路结构适用性的比选研究

从哈尔滨市常用筑路材料的特性入手,系统介绍了该地区的常用道路结构组合,通过对其弯沉、拉应力、容许拉应力等检测指标及造价的分析比较,提出了各种道路结构的适用性、缺点,给出了适用于哈尔滨市地区的道路结构方案。     

浅析筑路机械在高速公路养护中的科学管理

对筑路机械设备管理中存在的问题进行了分析,提出科学管理筑路机械设备的方法。     

超大粒径沥青混合料高温稳定性研究

为了研究超大粒径沥青混合料(SLSM)的高温稳定性,在借鉴大粒径沥青混合料(LSAM)研究方法的基础上,确定SLSM的级配,并以SBS改性沥青作为粘结材料,利用车辙试验的动稳定度评价SLSM的高温性能,并与普通密级配沥青混合料进行比较。结果表明:超大粒径沥青混合料的动稳定度比普通密级配沥青混合料的大17.07%,用作沥青路面的下面层满足要求。     

路侧隔离设施引起的路面狭窄效应研究

路面狭窄效应是一种负面的交通心理学现象,在布置交通设施时应尽量减小其对路面交通的影响.文章结合调查实例,通过计算路面狭窄效应衰减率,研究了路面狭窄效应对路面交通影响的原理与影响程度,具体探讨了路面狭窄效应与道路宽度、路侧隔离设施高度及路边建筑距离的关系.