交通冲突技术在ETC安全评价中的应用研究

由于数据缺乏,国内外有关ETC对交通安全影响的评价研究开展甚少。ETC系统对交通安全究竟会产生怎样的影响,如何进行分析评价,是一个全新的课题。作者参考了其它交通设施的安全评价方法并结合我国交通安全管理的实际情况,得出了仅运用事故统计数据模型来评价ETC对收费区安全水平的影响是欠可靠的这一结论,确定采用以非事故间接评价方法暨交通冲突技术对ETC安全进行评价。本文旨在确立ETC系统的安全评价方法并搭建其评价框架,着重探讨了如何在收费区引入交通冲突技术。     

网络条件下高速公路收费费率优化方法研究

以区域公路网为研究对象,在分析高速公路收费费率与交通量之间关系的基础上,建立收费费率优化双层规划模型,兼顾经营者和使用者的利益,并考虑路网交通流分布,设计了模型的实用求解算法。该方法弥补了已有方法多以运输通道为研究对象的不足之处,可以在收费系数确定的情况下根据优化目标直接得到优化结果,具有较为广泛的适用性。     

交织区长度对车道变换频率的影响

交织区长度是影响交织区运行特性的重要参数,影响着交织车辆进行车道变换的紊动程度。找出了车道变换频率与其相应产生的车道变换长度的一一对应关系,定义了车道变换长度随机变量,通过分析给定交织区车道变换长度的统计分布来反映交织操作车道变换的频度。在其他因素不变的条件下,运用动力学理论、概率论等方法定量分析了交织区长度对车道变换产生的影响。     

Experimental Study on Mechanical Behaviors of Prefabricated Column-Base Joint with Grouted Sleeves Connecting Longitudinal Reinforcements in Tunnels北大核心CSCD

In recent years, large shield tunnels with internal double-decked lanes have been developing rapidly in the field of highway tunnels, and prefabricated elements are increasingly adopted in internal structure. Based on the columns-base joint in Zhuguanglu tunnel, which is under construction, 2 full-scale specimens are designed for the quasi-static test, one specimen is connected with grout sleeve splicing and the other is cast in place. The test results show that: the bearing capacity of specimen with grout sleeve splicing is equal to that of cast-in-situ specimen, but its ductility and energy dissipation capacity are worse than that of the cast-in-situ specimen. And for the specimen with grout sleeve splicing, there exists crack concentration on the area above the sleeve. The crack width is too larger in this area. © 2018, Editorial Office of "Modern Tunnelling Technology". All right reserved.     

Physical environments influencing bicyclists’ perception of comfort on separated and on-street bicycle facilities

This study investigates the impacts of physical environments on bicyclists’ perceptions of comfort on separated and on-street bicycle facilities. Based on a field investigation conducted in Nanjing, China, we find that physical environmental factors significantly influencing bicyclists’ perception of comfort on the two types of facility. Cyclists’ comfort is mainly influenced by the road geometry and surrounding conditions on physically separated paths while they pay attention to the effective riding space and traffic situations on on-street bicycle lanes.     

里双桥重建工程道路改建方案设计

合理的横断面形式、平纵线形指标、路基路面设计是城市道路改建中的关键。结合苏州老城区道路改建项目,针对现状建设条件、交通量预测结果,推荐采用三块板断面布置形式。通过拆除原侧分带、压缩非机动车道形式,使现状双向四车道实现双向六车道,同时新建侧分带保留了四排绿化,充分考虑了老城区道路绿化景观需求。拓宽新建段一般路基设计采用20 cm C20混凝土处理,路面设计根据现状弯沉值推荐了两种方案,为城市道路改建工程提供经验参考。     

We can all get along: The alignment of driver and bicyclist roadway design preferences in the San Francisco Bay Area

Two trends in the United States—growth in bicycling and enthusiasm for complete streets—suggest a need to understand how various roadway users view roadway designs meant to accommodate multiple modes. While many studies have examined bicyclists’ roadway design preferences, there has been little investigation into the opinions of non-bicyclists who might bicycle in the future. Additionally, little research has explored the preferences of the motorists who share roads with cyclists—despite the fact that motorists compose the vast majority of roadway users in the United States and similarly developed countries.This paper presents results from an internet survey examining perceived comfort while driving and bicycling on various roadways among 265 non-bicycling drivers, bicycling drivers, and non-driving bicyclists in the San Francisco Bay Area. Analysis of variance tests revealed that both drivers and bicyclists are more comfortable on roadways with separated bicycling facilities than those with shared space. In particular, roadways with barrier-separated bicycle lanes were the most popular among all groups, regardless of bicycling frequency. Striped bicycle lanes, a common treatment in the United States, received mixed reviews: a majority of the sample believed that they benefit cyclists and drivers through predictability and legitimacy on the roadway, but the lanes were rated significantly less comfortable than barrier-separated treatments—particularly among potential bicyclists.These findings corroborate research on bicyclists’ preferences for roadway design and contribute a new understanding of motorists’ preferences. They also support the U.S. Federal Highway Administration’s efforts to encourage greater accommodation of bicyclists on urban streets.     

Estimating the bus user time benefits of implementing a median busway: Methodology and case study

This paper presents a general framework to estimate the bus user time benefits of a median busway including the effects on travel time and access time. Unlike previous models, we take into account the effects of geometry and the interaction with the demand structure. Models for predicting the bus in-vehicle time benefits of a median dual carriageway busway against mixed traffic condition on 2 and 3 lanes roads are estimated using data from a case study in Santiago (Chile), using a bus travel time model empirically estimated and considering different base case situations, including mixed traffic operations and bus lanes. Results of the application show that the expected in-vehicle time savings of a median busway might be reduced by access time losses due to increased walking distances and road crossing delays. Also, that net time benefits can vary significantly according to the base situation and the structure of demand considered. These findings point out to the need of including a wider set of impacts when studying the benefits of median busways, beyond in-vehicle time savings only. The empirical work presented here is completely based on passive data coming from GPS and smartcards, what makes easier and cheaper to conduct this type of analysis as well as to do it with a comprehensive scope at an early stage of the development of a BRT project. This framework can be extended to other types of dedicated bus lanes provided that a corresponding bus travel time savings model is available.     

辽宁省高速公路管理局收费中心系统改造分析

简要说明辽宁高速公路中心收费系统升级改造方向,结合辽宁高速公路收费系统现状,提出适合辽宁高速公路中心系统升级的解决方案.     

三峡水库主要通航支流船舶定线制的设计原则和基本方法

本文参照国际海事组织关于船舶定线制的设计规范和标准,依据《中华人民共和国内河交通安全管理条例》、《中华人民共和国内河避碰规则》等法律、法规,对三峡水库通航支流船舶定线制的设计原则和基本方法,进行了探索和研究。