PPP融资模式在城市基础设施工程中的应用研究——以南昌市红谷隧道工程为例

PPP建设模式具有减轻政府财政压力、提高项目建设和运营效率、风险共担等优点,可为城市基础设施提供重要的资本及专业支持,拓宽社会资本投资渠道。以南昌市首个采用PPP建设模式的城市基础设施项目--南昌市红谷隧道工程为例,分析在该融资模式下城市基础设施工程建设和运营期的效果以及存在的问题。结果表明： 将PPP模式运用于红谷隧道工程中,可有利推动项目的建设,使得项目在投资、进度和质量等方面得到很好的控制,同时,在运营阶段也取得很好的效果。     

浅议交通基础设施建设项目利用BT方式融资的利与弊

通过论述交通基础设施建设项目利用BT方式融资的利弊,为交通建设项目探索新的融资模式提供参考。     

车路集成环境下车辆防撞预警安全状态判别模型的研究

针对现有安全状态判别模型未能兼顾行车安全与道路空间资源利用率,且忽略了实际行驶环境下动态制动减速度信息的问题,提出了车路集成条件下车辆防撞预警安全状态判别模型。通过车-路通信协作实现对路面类型等实际行驶环境因素的动态识别,并确定车辆采取制动措施时所能获得的动态制动减速度;通过分析前车与自车的有效制动时间和车辆制动全过程,建立了新型临界跟车距离模型,并给出了模型关键参数的获取方法。仿真结果表明,该判别模型具有较强的自适应性,更贴近车辆实际行驶环境下的制动过程,有利于提高道路空间的利用率。     

Adaptive road border crossing system management: the role of priority programs

Land border crossings in North America, such as those between Canada and U.S.A., are expected to experience severe imbalance of travel demand and capacity of processors. During peak travel periods, this is already the case at high traffic locations. The land border crossing authorities have to address problems of congestion, national security and environmental impacts in the operation of the existing systems and to continue to address these problems as a part of infrastructure expansion plans. There is a need to adapt the crossing system management in order to accommodate efficiency and productivity‐oriented priority crossing measures. From a methodological perspective, it is a challenge to evaluate the role of priority crossing measures within the complex border crossing system. This paper reports research on modelling priority crossing initiatives. A microsimulation approach was used to model and analyse integrated processors of the Peace Bridge crossing system between Fort Erie (Ontario) and Buffalo (New York) under different scenarios of travel demand, customs processing times, priority crossing and queue jump lanes for automobile and truck traffic. Findings show the extent to which a border crossing system with priority crossing and queue jump lanes is more efficient and productive than one without these innovations. Copyright © 2011 John Wiley & Sons, Ltd.     

面向不同管理需求的交通基础设施养护数据平台建设

为了掌握交通基础设施技术状况、服务于养护技术经济指标分析,基于不同层级管理目标的信息化需求,通过详细分析不同层级需求的数据及其来源,设计了可服务于不同管理层级并用于管理主体交互的基本数据组成、获取和更新路径。此外,以数据设计为基础,展示了数据平台应用于申嘉湖高速公路的管理案例。     

公路基础设施资产管理概述

参考国内外有关资料阐述了公路基础设施资产管理的基本概念、总体架构，就资产管理系统及系统方法论的应用和寿命周期成本分析方法等进行了探讨。     

基于车路协同的无控十字路口行车方案

针对紧急车辆在无信号控制十字路口处通行效率低和事故频发的问题,基于SUMO与OMNet++的双向耦合车联网仿真平台Veins中搭建了车辆运动控制系统模型,设计路口处紧急车辆与普通车辆碰撞的判定方法和紧急状况下车辆避免碰撞行车措施,提出基于车路协同技术的无控十字路口紧急车辆行车方案.在Veins车联网仿真平台上对行车方案...     

基于自然驾驶数据的跟车场景潜在风险评估

为弥补传统风险评价指标对相对速度较小的跟车场景危险水平评价能力的不足,减少跟车场景中追尾事故的发生,提出了跟车场景潜在风险的概念。将假定前车以较大制动减速度减速条件下的风险称为潜在风险,并构建了代表驾驶人在潜在危险跟车场景下进行避撞操作需满足的最大反应时间的参数时间裕度（TM）。由于追尾危险工况中常见采取的避撞操作可分为制动和制动转向两大类,分别对典型制动避撞过程和制动转向避撞过程进行了分析,从而推导出分别针对2种跟车潜在危险场景的TM计算方式。通过自动筛选与人工筛选结合,获得了中国自然驾驶数据库（China-FOT）中具有中国驾驶人特点的制动避撞危险工况87个和转向制动避撞危险工况40个进行分级,并基于图像处理方法提取了前车制动开始时刻的TM值,从而得到跟车场景潜在风险两级危险域的划分。结果表明：制动避撞场景下,本车车速过低和过高时,TM值的变化均不明显;而在制动转向避撞场景中,只有速度较高时阈值才保持不变。通过对正常驾驶视频的分析,引入对比组共计正常跟车制动工况163例和正常跟车转向变道工况151例的车头时距（THW）值,其统计分析结果与支持向量机分类结果均难以清晰描述跟车场景危险水平与本车速度之间的关系。为研究跟车场景潜在风险评价在自动驾驶中的应用,对于制动避撞场景,在设定TM值不变和相对速度不变的条件下,分别对基于TM的最小相对距离和距离碰撞时间（TTC）值进行了仿真,仿真结果显示,相比于TTC而言,TM的评价稳定性受相对速度影响小,在自动驾驶跟车策略开发和避免其发生责任追尾事故中有重要应用价值。     

Assessment of port economic impacts on regional economy with a case study on the Port of Lisbon

This article presents a method of assessing the economic impacts of ports at both regional level and national level, through application of input–output analysis. To this end, a methodology for data collection is proposed, which combines a top-down with a bottom-up approach which should help in surpassing some of the difficulties commonly faced in port economic impact studies. The presented methodology allows port planners and policymakers to assess the economic significance and geographic reach of port investments. This study considers the economic impacts of the port cluster and the socio-economic significance of port user industries. The several layers of the analysis are kept separate to allow a better grasp of direct and indirect impacts. The proposed methodology is demonstrated in a study of the Port of Lisbon, which confirms the significance of this port to the Portuguese economy, and also demonstrates that the influence of the Port of Lisbon is mostly limited to an area in close proximity to the port. Therefore, results suggest that investments for the development of logistic infrastructures associated with the port should concentrate in the immediate hinterland of the port.