山区公路行车视距分析

驾驶员应有足够的视距来判断车辆前方发生的变化,以便采取相应措施确保车辆安全行驶。从山区公路交通流特点和事故成因出发,对平面视距和纵面视距的行车安全性进行了分析,同时从保障行车安全角度总结了行车视距设置应考虑的影响因素,对山区公路路线设计起到一定的指导作用。     

弯道诱发道路交通安全事故分析

道路交通安全关乎我们的切身利益,其诱发因素颇多,而弯道是交通安全事故高发地。文章从汽车行驶特性、不良视距、会车超车等方面入手,分析弯道诱因与交通安全事故间的内在关系,并提出了基于GPS、GIS信息系统工程的智能交通预警思路,为交通安全控制提供理论参考依据。     

公路车速限制与行车安全视距关系的探讨

通过对新建公路限制车速与行车安全视距值之间的关系探讨,对新建公路限制车速采用的行车安全视距值与影响因素进行量化,提供了新建公路限速选用的行车安全视距范围,可供道路工程设计及高等级公路管理人员参考.     

城乡结合部道路交通安全设计的要点

城乡结合部区域具有显著的独特性,其中城乡结合部的道路最为特殊,道路上汇集着各种各样的车辆,存在着极大的交通安全隐患,为此必须加强此区域道路的交通安全设计。本文主要总结城乡结合部的道路交通安全设计要点,包括保证视距适宜、平面线形合理、科学的机非分离设计、科学设计道路两侧设施、设置明显的交通标识,从而提高城乡结合部的道路安全性,更有效地维护城乡结合部道路上通行人员的安全。     

轻型汽车道路行驶阻力的测量与模拟

文章介绍了汽车道路行驶阻力的测量原理、底盘测功机模拟原理和惯量模拟原理;对欧美日三个标准体系中的道路行驶阻力测量方法进行了介绍,以实例对三个标准体系下计算的道路行驶阻力进行了验证和对比。结果表明,三种测量方法所得道路行驶阻力基本一致。     

车用电子设备让汽车更具安全性

在道路上所有主要交通工具,包括:机车、汽车、公车,及大众轨道等交通工具,若将交通工具的发展趋势进行排序,应该是安全、环保及性能,而安全问题应该被放在第一;因此,汽车行驶的安全性能将会是所有人感兴趣的话题,而科技技术将改善未来汽车能具备更安全且有保障的乘坐空间.     

重庆桥梁交通安全状况调查与改善技术研究

频繁发生的客车坠桥事故造成了重大的人员伤亡和财产损失,提高桥梁运营安全水平工作十分迫切。文章在对重庆市桥梁交通安全状况调查的基础上,分析了桥梁路段在设计、管理、交通运行等方面存在的问题,提出从桥头视距、道路养护、警示设施设置、中央分隔带设置等方面进行综合整治的安全改善措施,为桥梁的安全设计与管理提供参考。     

道路运输车辆动态监督管理办法

<正>第一章总则第一条为加强道路运输车辆动态监督管理,预防和减少道路交通事故,依据《中华人民共和国安全生产法》、《中华人民共和国道路交通安全法实施条例》、《中华人民共和国道路运输条例》等有关法律法规,制定本办法。第二条道路运输车辆安装、使用具有行驶记录功能的卫星定位装置(以下简称卫星定位装置)以及相关安全监督管理活动,适用本办法。第三条本办法所称道路运输车辆,包括用于公路营运的载客汽车、危险货物运输车辆、半挂牵引车以及重型载货汽车(总质量为12吨及以上的普通货运车辆)。     

基于车载测试的CNG汽车微观排放特性研究

为了分析CNG汽车道路排放的微观特性,采用车载排放测试系统,并选取市区主要道路为试验路段进行了实车道路试验。通过试验获取典型车辆的排放数据及行驶状态,分析车辆在实际行驶中的排放特性,为预测不同交通状态下CNG汽车的排放特性和区域排放清单建立提供参考。     

CASIO fx-4800P道桥施工测量计算程序

该程序为fx-4800P计算器专用。程序主要用于铁路、公路中线施工测量，铁路桥梁工作线计算，道路边桩和桥梁设计坐标测设及竖曲线高程计算。给出了源程序及使用功能介绍，并对输入输出符号作了定义。     

Development of transitioned vertical curve I Properties

Introducing spiral curves before and after horizontal circular curves has been widely accepted to enhance traffic safety, highway esthetics, sight distance, and driver comfort. Though, vertical curves are still designed as parabolic curves that are connected directly to the tangent (without transitions). In this paper, a cubic polynomial is used to develop a vertical transition curve before and after the parabolic vertical curve. The resulting curve, called transitioned vertical curve, consists of transition-parabolic-transition segments. Detailed mathematical formulation and derivation of the instantaneous elevation, grade, rate of curvature, and offset from the first tangent at any point are presented. The highest (or lowest) point on a transitioned crest (or sag) vertical curve, where the instantaneous grade equals 0, is determined as it is of particular importance in highway drainage design. The minimum length of a transition curve is derived based on the criterion of driver comfort. In addition, guidelines are provided to identify the conditions where the drainage of surface water on transitioned curves can be a concern. Finally, the layout of the transitioned vertical curve is described and illustrated using two numerical examples. The new transitioned vertical curve, which exhibits striking similarities to the spiraled horizontal curve, should enhance the design of highway vertical alignments.     

Development of transitioned vertical curve II Sight distance

The mathematical properties of a new vertical curve that consists of a transition curve (cubic polynomial), a parabolic curve, and another transition curve have been presented in a companion paper. The present paper addresses the sight distance characteristics of this new curve, called transitioned vertical curve. The minimum sight distance and the required curve length are analytically derived for both crest and sag curves, considering various cases related to the minimum sight distance and the lengths of transition and parabolic curves. Using the developed analytical models, example design graphs are established for the length requirements of the transitioned vertical curve based on the upper range of stopping sight distance presented by the American Association of State Highway and Transportation Officials. The transitioned vertical curve, which resembles the spiraled horizontal curve commonly used in practice, represents an alternative to the simple vertical curve especially for sharp vertical alignments.     

Modeling of individual vehicle safety and fuel consumption under comprehensive external conditions

This research intends to explore external factors affecting driving safety and fuel consumption, and build a risk and fuel consumption prediction model for individual drivers based on natural driving data. Based on 120 taxi drivers’ natural driving data during 4 months, driving behavior data under various conditions of the roadway, traffic, weather, and time of day are extracted. The driver's fuel consumption is directly collected by the on-board diagnostics (OBD) unit, and safety index is calculated based on Data Threshold Violations (DTV) and Phase Plane Analysis with Limits (PPAL) considering speed, longitudinal and lateral acceleration. By using a linear mixed model explaining the fixed effect of the external conditions and the random effect of the driver, the influences of various external factors on fuel consumption and safety are analyzed and discussed. The prediction model lays a foundation for drivers' fuel consumption and risk prediction in different external conditions, which could help improve individual driving behavior for the benefit of both fuel consumption and safety.     

隧道内烟道板植筋牛腿耐火试验研究

介绍了上海长江隧道烟道板支座牛腿植筋的耐火试验设计和试验过程。试验测试了牛腿在承受垂直静荷载以及碳氢标准升温曲线共同作用下的响应，通过温度、变形等试验数据的采集和分析研究，把握了用植筋方式构筑的支座牛腿的实有安全度，为结构设计优化和其他类似工程提供了可信的基础依据。     

Impact of traveler advisory systems on driving speed: some new evidence

This paper explores the effects of driving behavior using in-vehicle and out-of-vehicle traffic advisory information relating to adverse weather and incident conditions. A full-size, fixed-based driving simulator is used to collect data on drivers’ speed behavior under four different advisory-information conditions: in-vehicle messages, out-of-vehicle messages, both types of messages, and no messages. The findings of this study suggest an interesting phenomenon in that, while messages are significant in reducing speeds in the area of adverse conditions, drivers tend to compensate for this speed reduction by increasing speeds downstream when such adverse conditions do not exist. As a result, the net safety effects of such message systems are ambiguous.     

公路路线设计中运行速度理论检验的方法

我国目前的公路路线设计采用设计速度理论,设计速度是个定值,而多年的实践表明,车辆实际的运行速度总是随公路线形等条件的改变而变化,所以设计速度理论本身存在一定的局限性,需要采用动态的运行速度对公路的路线设计进行安全性检验,以确保行车安全。文章结合设计实例,探讨公路路线设计中运行速度理论检验的方法。     

Measuring the success of reducing emissions using an on-board eco-driving feedback tool

This paper reports the findings of an eco-driving trial that was designed enable users to make pre-trip and on-route decisions when driving as to the optimal route to take. The basis of this paper will be to estimate how efficiently drivers are performing in relation to fuel consumption per kilometres (km). The analysis uses details on the vehicle specification, in terms of fuel efficiency, and relates this to the distance travelled to provide the user with information on the efficiency per km travelled. Eco-driving involves the training of individuals to change their driving patterns and to adapt to driving conditions. The results of the study show that eco-driving feedback is a powerful tool and how it can be used to reduce emissions.     

Importance of scenic byways in route choice: a survey of driving tourists in the United States

In order to develop more effective tourist information systems for use along scenic byways, it is important to know the characteristics of those people who include the presence of scenic byways in their selections of routes. Gaining a better understanding of these characteristics was the purpose of this study. The data presented here are from a United States (US) survey of the driving tourist's information needs and preferences weighted to be representative of US tourist travelers. The study showed that when planning a route to a destination on an overnight automobile trip, the driving tourist is most concerned with factors related to the actual driving of the route, such as the directness, safety, amount of congestion, and distance. Of secondary importance are factors that make the route entertaining or pleasant to drive, including whether the route is a scenic byway. Analysis of the importance of scenic byways by several demographic factors showed little difference in importance ratings except for age and household income. Examination of importance ratings by trip characteristics showed that the presence of scenic byways in selecting a route was more important for the traveler whose trip purpose is a vacation, who is in the midst of a long distance and duration trip, who will be either camping or staying in a hotel, and who has planned the trip well in advance. These results suggest that scenic byways are an excellent area for the implementation and testing of in-vehicle information systems for the driving tourist.