Winter problems on mountain passes – Implications for cost-benefit analysis

Cost-benefit analysis is a tool in government decision-making for determining the consequences of alternative uses of society’s scarce resources. Such a systematic process of comparing benefits and costs was adopted in early years for transportation projects and it has been the subject of much refining over the years. There are still some flaws, however, in the application of the method. In this article we have studied the impact of weather conditions on traffic speed on low traffic roads often exposed to adverse weather. This is an issue not currently considered in the cost-benefit analysis of road projects. By using two analytical approaches—structural equation modelling and classification and regression tree analysis—the impact of the weather indicators temperature, wind speed, and precipitation on traffic speed has been quantified. The data relates to three winter months on the European Route 6 road over the mountain pass Saltfjellet in Norway. Increase in wind speed, increase in precipitation and temperatures around freezing point all caused significant decrease in traffic speed in the case studied. If actions were taken to reduce the impact of adverse weather on traffic (e.g. by building a tunnel through the mountain) this study indicates that the road users would gain a total benefit of approximately 2,348,000 NOK (282,000 EUR) each winter at Saltfjellet if all the weather related benefits were included. We argue that this is a significant number that is highly relevant to include in CBAs. This applies both to the CBAs of new transportation projects as well as when resources are allocated for operation, maintenance, and monitoring of the existing transport systems. Including the weather related benefits would improve the application of CBA as a decision-making tool for policy makers.     

Stimulating Vertical Integration in Coastal Management in a Federated Nation: The Case of Australian Coastal Policy Reform

Four decades ago Australia was credited as being an early leader in implementing integrated coastal management (ICM). Nevertheless, as a federation of states and territories Australia has since struggled to fully implement vertical integration of its coastal governance arrangements. In particular the federal government has historically possessed only a minor role in coastal management despite the recommendations of several major inquires suggesting that this role needed to be enhanced. This article examines a series of circumstances and events over the past two years in Australia that has created the opportunity for the federal government to adopt a more significant and prominent role in coastal management and hence to substantially complete the vertical integration of ICM in Australia. These stimuli for coastal policy reform could also play a role in enhancing ICM in other federated nations.     

汉画像石与封建“孝”

秦汉时期是中国封建社会的上升时期,这一时1期统治者的统治策略不断发生变化,至汉武帝时,“忠孝”思想成为中央及地方各种社会活动的准绳,而后“孝”的发展进而滋生了一种陋俗—一薄养犀葬,在“孝”的思想的主宰和薄养厚葬之风气的双重影响下,墓葬艺术得到空前发展,为后世留下了辉煌的艺术财富…汉画像石。它虽然以尽孝为目的,然而却在无意中涵括了秦汉时期的艺术气象,通过画像石的形成和发展轨迹来探寻它与封建“孝”的关系。     

雨天环境下高速公路可变限速控制方法研究

降雨对高速公路交通安全和通行效率具有一定的负面影响.运用可变限速控制技术,根据高速公路实时交通流状态和降雨强度,对各路段限速值进行动态优化和调整,减小降雨带来的不利影响.阐述了雨天可变限速控制系统的总体方案,分析了降雨对能见度和路面摩擦系数的影响,建立了雨天环境下高速公路安全车速计算模型;在宏观动态交通流模型METANET基础上,提出了适用于雨天可变限速控制条件的改进模型,并以控制周期内所有车辆总行驶里程最大为目标,建立了雨天可变限速控制优化模型.利用Matlab软件仿真实验,结果表明,与固定限速方式相比,本文建立的可变限速控制方法可提高雨天环境下高速公路车辆运行速度,并降低各路段车速差,保障雨天环境下高速公路安全高效运行.     

综合舰桥系统综述

简要介绍了综合船桥系统的发展过程,阐述了舰桥系统的特点,提出了舰桥系统研究内容.这对舰船控制实现自动化,指挥决策科学化,提高舰船安全性具有重要意义.     

期租合约下的航速计算和索赔

期租下的履约航速计算结果涉及到航速索赔和燃油索赔,关系到船舶的营运成效,因而航速计算显得很重要。航速计算和索赔涉及期租合约及相关条款的订立和良好天气的定义、根据租约相关条款采用的计算方法、良好天气下的航速计算、气象导航公司的评估报告。     

极端天气下的安全驾驶技巧研究

众所周知,我国目前交通压力过大,在极端天气的影响下,交通事故频繁发生,这主要是由于驾驶者对于极端天气下的安全驾驶技巧过于生疏。基于此种情况,本文将主要围绕极端天气下的安全驾驶技巧进行研究,分别探讨有关冰雪天、雨天的安全驾驶技巧,以此为驾驶者提供参考,旨在降低交通事故的发生率。     

高速公路不良天气交通事故分析

不良天气导致路面使用性能下降是引发交通事故的重要原因之一。在对不良天气导致路面抗滑性能下降的机理及路面抗滑性能、能见度对交通安全的影响等进行了分析之后,通过对我国某高速公路不良天气交通事故发生特点的调查和分析,总结了不良天气交通事故发生率和发生形态,并对我国进行不良天气道路交通事故研究和统计方法等提出了建议。     

降雪条件下城市快速路交通流特性研究

以北京市交通流固定检测器数据为基础,对比分析了正常天气条件和降雪条件下北京市快速路交通流特性的差异,定量描述了降雪对北京市快速路流量和平均运行速度的影响。研究表明,大雪条件下,快速路流量约下降约39%,速度降低10～20km/h,来车时距普遍增加2～4s,饱和流率下降约25%。在此基础上,给出了北京市不同降雪强度下快速路的流量和当量流量水平下平均速度的折减系数。     

群体性治安事件的构成要件及公安机关预警处置机制

近年来,群体性治安事件,在数量和规模上趋于不断增大的态势,参与的人数较多,组织性也越来越强,行为方式也较为激烈,这就为公安机关的预警和处置带来更大的难度。本文试图对群体性治安事件的构成要件及公安机关的预警处置机制做初略探讨。