【作者】 祝站东；

【导师】 周伟；

【作者基本信息】 北京工业大学 ， 交通运输规划与管理， 2011， 博士

【摘要】 随着公路建设的快速发展与我国机动化程度的不断提高,交通在为人们带来快捷便利、经济舒适的同时,安全问题也越来越成为一个社会热点问题。在人、车、路所构成的交通系统中,不良的道路状况是交通事故的重要诱因之一。路线设计中现行的设计速度理念关注的是单个路段设计指标的安全性,往往忽视了相邻路段的安全性,即相邻路段的运行速度协调性。为了指导今后的路线设计以及安全性评价工作,有必要对运行速度相关理论展开更进一步的研究。我国公路构成中超过75%以上均为双车道公路,因此,深入研究双车道公路的运行速度相关理论,将有助于完善运行速度理论体系,对于我国今后的公路建设与管理具有重要的理论意义与应用价值。双车道公路横断面布置变化多样,设计中的指标运用较为灵活,道路沿线的路侧环境也比较复杂多变,单纯的从路线的平纵线形指标来建立运行速度模型显得很不全面。因此,必须综合分析影响运行速度的各种不同因素,在此基础上建立双车道公路的运行速度模型。通过试验深入分析了双车道公路的运行速度特征,基于不同行驶状态下车头时距变化和速度差波动规律,确定出车头时距为自由流状态的度量指标,认为自由流的界定标准应取车头时距9 s以上。在干燥和潮湿状况下,运行速度在统计意义上差别不大,可以认为没有必要对路面的干湿状况进行限定。通过分析运行速度各统计值的离差,分析了统计值的分布特征,认为选取路段特征点上测定的速度累计分布曲线上第85百分位对应的速度值作为运行速度是合理的。在此基础上,对于影响运行速度的各个因素进行了分析,认为运行速度受道路线形与道路环境综合影响,提出了运行速度理论模型。双车道公路首先应建立基准运行速度模型,然后建立道路环境对基准模型的修正模型。基准运行速度模型完全由道路几何线形所决定,双车道公路的路段单元根据平纵指标分为直线段、平曲线段、纵坡路段与弯坡路段。直线段的速度取决于直线段长度、直线接平曲线半径的大小以及驾驶人的期望。通过试验研究了直线路段上的车辆加减速特性,建立了加减速模型,通过运动学理论分析了直线段长度、初速度以及地区类别与运行速度之间的关系,建立了直线路段的运行速度模型。平曲线路段的运行速度取决于平曲线半径、平曲线长度以及初速度,通过大量的数据调查,利用统计回归的方法建立了平曲线路段的运行速度模型。根据运动学理论,纵坡路段的运行速度与车辆的动力性能有关,分析了运行速度与坡度、初速度等之间的关系,建立了纵坡路段的运行速度模型。弯坡路段的运行速度与初速度、平曲线半径、纵坡坡度、竖曲线前后坡度差有关,通过大量的数据调查,建立了弯坡路段的运行速度模型。双车道公路道路环境可以将分为两类,一类属于随机因素,可以称为路侧横向干扰,包括路肩停车、路肩行人、非机动车等,另一类是道路的固有属性,包括视距、路侧净空、街道化以及出入口。通过驾驶模拟舱研究了不同能见度(对应视距)下车辆的稳定速度变化趋势,分析了视距的变化对运行速度的影响,得到了视距受限路段的运行速度理论模型,然后通过实地数据采用逐步回归方法建立了视距受限路段的运行速度模型。针对不同的路侧净空,研究中通过实地的数据调查分析认为,路侧净空与运行速度之间呈对数关系,得到了路侧净空对基准运行速度的修正系数。驾驶人在街道化路段上行驶时,首先有一种预期,街道化路段上的行车是不安全的,因此,即使是视线范围里面没有出现不安全因素,驾驶人也会选择减速行为,其选择的行驶速度与道路两侧的空间大小有关。通过针对性的调查分析,得到了街道化路段的运行速度模型。出入口多是双车道公路的一个重要特点,通过延误调查,论文研究了出入口密度对运行速度的影响并建立了相关模型。路侧干扰对运行速度的影响主要与路侧干扰因素的数量、类别以及横向间距有关,论文研究了不同类别的干扰物对车辆的速度影响,通过理论分析建立了干扰物到达率与横向间距综合作用下的路侧干扰系数模型。通过分析事故的发生机理,认为交通事故的诱因是行驶过程中的交通事变,因此路线设计应做到指标变化的宜人性与平顺性,尽量避免引起运行速度突然变化的设计要素。进一步通过试验研究了车辆行驶过程中驾驶员的心率变异性和工作负荷度与设计速度一致性、运行速度协调性、速度降低系数及速度梯度之间的关系,得到结论认为,衡量路线安全性的指标应选用运行速度协调性和速度梯度两个指标。速度协调性|△V85|评价标准为:|△V85|≤10km/h,运行速度协调性好;|△V85|为10-20km/h:运行速度协调性较好,条件允许时宜适当调整相邻路段技术指标,使运行速度的差值小于或等于10km/h;|△V85|≥20km/h:运行速度协调性不良,相邻路段需要重新调整设计。速度梯度G v评价标准为: G v<0.10,路线安全性较好;0.10≤G v<0.15,路线安全性一般; G v≥0.15,路线安全性差,相邻路段需要重新调整。在此基础上,论文提出了双车道公路路线安全性评价方法,为今后的路线设计与速度管理提供了理论支持。更多还原

【Abstract】 With the rapid development of highway construction and the degree of the improvement of mobility, although traffic brings an efficient and convenient for people, economic and comfort at the same time, its security has increasingly become a hot social issue. In the system consist of human, vehicle and road, poor road conditions is one of the important causes of traffic accidents. The current concept of routh design conserns the safety of a single section, but often neglects the safety of adjacent sections, namely, the operating speed of the adjacent sections of coordination. In order to guide future road design and safety evaluation, it is necessary to further expand the theory of the operating speed. Therefore, to lucubrate the relate theory of operating speed of two-lane highway, composition of more than 75% of all highway, will help to improve desigh theory of operating speed , which has important theoretical significance and application to our future road construction and management.Two-lane highway has diverse cross-section, and the design indicators are more flexible, the road environment along the road is also more complex. To create models of operating speed with simple line indicator seems uncomprehensive. Therefore, the models of operating speed must be a comprehensive analysis of various factors, and based on these the models of operating speed of two-lane highway can be built .Experiments had been performed to analyze the change of continuous speed of the cars for experiments and study the change of the time headway and the fluctuation rules of the speed differentiae. Then time headway was regarded as the measurement index of free-flow, and time headway of free-flow should be taken more than 9 s interval. In dry and wet conditions, operating speed is not very different in the statistical sense, and it is unnecessary to limit the wet and dry conditions. By analyzing the value of the speed deviation and the statistical distribution of values,it is reasonable to selecte the 85 percentile of the cumulative speed distribution curve as operating speed. On this basis, the impacts of the various factors on operating speed are analyzed. Conclusion is made that the operating speed is determined by the combined effects of the road alignment and the road environment.Operating speed of two-lane highway should first establish a basic model, and then build modified model based on the road environments.Bisic speed model is entirely determined by road geometry.Two-lane highway section is divided into units as tangent sections, horizontal curves, veticle curves,and combination of horizontal and vertical,based on the index of geometry linetype. Operating speed of tangent sections depends on line length, the adjacent horizontal curve radius and the driver’s expectations. Experiments were drawn to study the acceleration and deceleration characteristics of vehicles, and the model of the acceleration and deceleration of tangents was built.Based on these, the model of the tangents was built between operating speed and initial speed, regional categories and the length. Section of horizontal curve speed depends on the horizontal curve radius, the length of horizontal curve and initial velocity.Large amounts of data were surveyed establish a horizontal curve section of the operating speed model, using statistical regression. According to kinetic theory, the speed of longitudinal section has close relation with dynamic performance of the vehicle.And the relation of the speed and the initial speed is analyzed and the model of the operating speed of longitudinal sections is built. Operating speed of combination of horizontal and vertical sections relates to initial speed, horizontal curve radius, the slope difference,and the model of operating speed is built bases on large amounts of data.Road environment two-lane highway can be divided into two categories, one is random factors,which can be called the road side interference, including the shoulder parking, shoulder pedestrians, non-motor vehicles, and the other is the inherent property of the road, including the sight distance, road-side clearance, and accesses of the road.The trend stable speed of the vehicle’s in the different visibility (corresponding to line of sight) is studied in driving simulator, and the the impact of sight distance on operating speed is analysed. The theoretical model between sight distance and operating speed is built, and then the mode of sections with limited sight distance is built through the field data using stepwise regression method. For different roadside clearance, through field data investigation and analysis, roadside clearance and operating speed show a logarithmic relation and then obtain the correction factor of roadside clearance on the basic model. When drivers travel on the streets of the road, the first is expected to have an insecure, that the streets of traffic on the section is not safe, so even if there is no line of sight of insecurity, the driver will choose to slow down. The behavior of their choice lies on both sides of the space and the size of the road. Through targeted investigation and analysis, the model of operating speed of streetlized highway is built. Mostly two-lane highway access is an important feature. Through delay investigation, the paper studied the relation between the access density and operating speed, and the the relevant model is built. The impact of roadside interference relate to the number of interfering factors, category, and horizontal spacing.The article studied the ampact of different types of roadside interference on the speed of the vehicle, and built the interference factor model by theoretical analysis of the horizontal distance and objects integrated arrival rate.By analyzing the mechanism of the accident ,the accident was triggered by the sudden change of the traffic system, and the route should be designed to be indicators of changes in the amenity and comfort, try to avoid sudden changes in the design elements. Then experiments were drawn to study the relations among the driver’s heart rate variability and work load degree and operating speed, and the indicators as consistency of design speed, operating speed coordination, speed and acceleration of lower coefficient and velocity gradient were studied to find the relation between safety and above indicators.The conclusion obtained that the road safety indicators should choosed as operating speed coordination and velocity gradient.Speed coordination evaluation criteria: |△V 85 |≤10km / h, good coordination; |△V85| for the 10-20km / h: common coordination, when conditions permited adjacent sections of technical indicators should be adjusted, so that the speed differentiate is less than or equal to 10km / h; |△V85 |≥20km / h: poor coordination speed, need to re-adjust the design of the adjacent sections. Velocity gradient evaluation criteria:Gv≤0.10, good road safety; 0.10≤Gv <0.15, common road safety; Gv > 0.15, poor road safety, the adjacent sections need to re-adjust. On this basis, the paper proposed two-lane highway safety audit of routes, providing theoretical support for the route design and the future speed management.更多还原