Short sleep duration,sleep disorders,and traffic accidents

Sleepiness is an important factor in traffic accidents caused by human error. The purpose of this paper is to review a number of studies conducted over the years regarding the effect of the lack of sleep on the incidence of traffic accidents as well as the individual effects of various sleep disorders on accidents. In addition, we discuss recent advances in methods of detecting sleepiness and strategies for preventing traffic accident by using these methods.     

Dynamic hardening behaviors of various marine structural steels considering dependencies on strain rate and temperature

This paper presents a new formula for prediction of the dynamic hardening effect for various marine structural steels, considering dependencies on the strain rates and temperatures. Dynamic tensile tests are carried out for three kinds of marine steels, 2W50, EH36, and DH36, changing the steel layer in the thickness direction, the strain rates, and temperatures. Considering two thickness layers at the middle and surface, five strain rate levels of 0.001/s, 1/s, 10/s, 100/s, and 200/s, three temperature levels of LT (−40 °C), RT, and HT (200 °C), and two repetitions, the total number of tests is 180. Dynamic hardening is clearly seen at LT and RT regardless of the material type, while dynamic strain aging occurs at HT, leads to negative strain rate sensitivity, and thus elevates the quasi-static flow stress above the dynamic flow stress to a certain strain rate. Dynamic hardening factors (DHFs) are derived as a function of the proof strains of 0.05, 0.10, and 0.15 according to each material type and temperature level. A new formula to determine the material constant D of Cowper–Symonds constitutive equation is developed. The correctness of the proposed formula is verified through comparison with test flow stress curves and reference test data in large plastic strain and high strain rate ranges.     

公路平面交叉口交通安全养护评价体系及方法研究

从公路平面交叉口交通安全养护需求出发,对平面交叉口交通安全养护评价指标体系和方法进行了系统研究和分析,形成了完整的公路平面交叉口交通安全养护评价体系。基于路基路面、安全设施、管理设施、交叉口渠化、绿化五个方面建立了平面交叉口交通安全养护评价指标体系;提出了评价指标数据采集方法和标准;验证了数据采集的一致性;建立了平面交叉口安全养护评价模型;标定出了模型参数;并选取试验路口利用模型计算值和专家主观打分均值的相关性分析,对建立的模型有效性进行了验证。     

西部某交通勘察设计企业发展战略转型研究

文章以西部某交通勘察设计企业为研究对象,对当前交通勘察设计企业所面临的内外部形势进行分析,并针对企业转型发展中所存在的问题,提出以创新为驱动的发展模式,总结归纳出推动企业可持续发展的相关对策,对类似交通勘察设计企业的转型发展具有一定的参考和指导意义。     

城市道路交通噪声污染经济损失及评估

文章应用市场估值法、享乐价格法和意愿调查价值评估法对城市道路交通噪声经济损失的货币化进行分析,并以北京市为例,计算评估了城市道路交通噪声带来的经济损失。     

城市桥梁声屏障设计及交通噪声控制研究

城市桥梁交通噪声污染随着城市道路的发展和车辆增多日益严重,引起了人们的普遍关注。文章以北大桥声屏障设计为研究对象,结合北大桥交通噪声污染调查分析,阐述了声屏障高度、声屏障结构形式等声屏障设计治理方案,并从规划阶段、运营阶段等方面探讨了城市桥梁交通噪声的控制对策。     

道路交通事故发生机理与实例分析

交通事故发生机理是认识道路交通事故发生过程、交通事故预防和改善交通安全的基础。文章以道路交通系统为研究对象,分析道路交通事故的形成过程,将交通事故发生机理分为驾驶行为差错类事故发生机理、外部因素突变类事故发生机理、综合性事故发生机理三类,并在此基础上绘制了道路交通事故发生机理图,同时结合国道109线兰州八盘村路段进行了实例分析。     

浅谈高速公路改扩建工程交通组织方案

文章结合广西沿海高速公路改扩建一期工程实例,阐述了高速公路改扩建工程施工阶段交通组织的总体方案,并介绍了在路基、路面、桥梁施工阶段的交通组织具体措施,为同类型高速公路改扩建施工提供参考。     

厦漳跨海大桥工程技术创新综述

福建省厦漳跨海大桥工程是一个在强风强震强腐蚀性海洋气候条件下,集2座特大跨径斜拉桥主桥、海上长大连续结构引桥和多种施工工法于一体的大型跨海桥梁系统工程。招商局重庆交通科研设计院有限公司（简称“重庆交科院”）承担了其工程可行性研究、总体方案确定、结构设计、技术保障,以及索缆、铺装、机电施工和试验检测等项目,为大桥建设付出了近10年的艰辛努力,也为工程创新技术的应用作出了重要贡献。     

Traffic conflict assessment for non-lane-based movements of motorcycles under congested conditions

Traffic conflict under congested conditions is one of the main safety issues of motorcycle traffic in developing countries. Unlike cars, motorcycles often display non-lane-based movements such as swerving or oblique following of a lead vehicle when traffic becomes congested. Very few studies have quantitatively evaluated the effects of such non-lane-based movements on traffic conflict. Therefore, in this study we aim to develop an integrated model to assess the traffic conflict of motorcycles under congested conditions. The proposed model includes a concept of safety space to describe the non-lane-based movements unique to motorcycles, new features developed for traffic conflict assessment such as parameters of acceleration and deceleration, and the conditions for choosing a lead vehicle. Calibration data were extracted from video clips taken at two road segments in Ho Chi Minh City. A simulation based on the model was developed to verify the dynamic non-lane-based movements of motorcycles. Subsequently, the assessment of traffic conflict was validated by calculating the probability of sudden braking at each time interval according to the change in the density of motorcycle flow. Our findings underscore the fact that higher flow density may lead to conflicts associated with a greater probability of sudden breaking. Three types of motorcycle traffic conflicts were confirmed, and the proportions of each type were calculated and discussed.