Safety impacts of signalized lane merge control at highway work zones

Lane closures due to highway work zones present many challenges to the goal of ensuring smooth traffic operations and a safe environment for both drivers and workers. Late merge behavior at a work zone closure is a dangerous behavior that impacts the traffic conflicts upstream of work zone closures. This paper analyzes the safety impacts of using a signalized lane control strategy at the work zone merge points. To achieve the objective of this research, a field study has been conducted at a highway work zone to collect traffic and driver behavior data, and a two-stage, simulation-based approach is used to analyze the safety impacts of implementing a signalized lane merge control strategy at the studied work zone. In the first stage, micro-simulation models are developed and calibrated based on field data to generate vehicle trajectories. In the second stage, the U.S. Federal Highway Administration’s Surrogate Safety Assessment Model is employed to identify potential conflicts under different traffic conditions. The paper concludes that a proposed signal control device could significantly reduce lane-change conflicts at work zone merge points. In addition, recommendations on the signal cycle length and timing splits are provided.     

Policy implementation of multi-modal (shared) mobility: review of a supply-demand value proposition canvas

ABSTRACT

Urban mobility options have increased in recent years, assisted by the widespread availability of smart device software apps, geo-positioning technology, and convenient electronic financial transactions. Multi-modal shared mobility consists of public transit systems and shared mobilities that support first/last mile travel, denoting the capability of Mobility as a Service (MaaS), and to stimulate additional non-private car travel demand. This paper reviews the supply and demand sides of implementation of multi-modal shared mobility. It found that an abundance of shared modes of car, bike, and e-scooter that are linked to public transport, can improve transport accessibility to meet specific public preferences, reduce social inequality, and minimise dilemmas from the demand side. This study introduces government policy innovations and other supporting system to improve the implementation of multi-modal shared mobility. Government policies play a key role in supporting shared mobility and technology development. However, governments do not have much information about new products such as shared mobility, which creates difficulties in subsidising multi-modal shared mobility services and potentially leads to policy failures around shared mobility schemes. This study suggests that policy entrepreneurship in collaboration with other partners, policy innovation, and the notions of merit goods and second-best policymaking can enable policy initiatives towards multi-modal shared mobility and provide supporting arguments if policies encounter failures. Implementing multi-modal shared mobility requires a collaborative partnership for a paradigm shift: service providers and government must jointly set a merit-based business model, with the support of organisations to achieve improved infrastructure provision, and smart technology applications. The findings will assist the community, business providers and government policymakers to promote multi-modal shared mobility as a pathway towards more efficient, environmentally sustainable, and socially responsive mobility solutions.     

分体式台车在城际铁路明挖隧道中的应用

先简单叙述了分体式模板台车的安装、使用及校核过程,通过台车操作平台控制千斤顶油压调节模板形状,人工测量校核达到设计要求位置。随后阐述了分体式台车施工方法及施工控制要点,分别就侧墙施工与拱顶施工做了描述,重点描述了施工过程中防水施工采取的措施,总结了明挖隧道施工过程中分体式台车的使用经验,证明了分体式台车在安全、质量、进度和费用方面的可行性与可操作性,对类似工程提供借鉴。     

Short Sea Shipping in Supply Chains. A Strategic Assessment

The feasibility of implementing short sea shipping (SSS) between two specific ports has been typically approached on the operative level, in terms of time and cost for a specific origin–destination pair. This paper focuses on the strategic level. Particularly, its goal is to study the potential of SSS in different industrial sectors by analysing their freight-distribution strategies. To achieve the objective, some standard freight-distribution strategies are defined based on the requirements of the industry, the demand and the product being transported. The information is complemented with a survey of more than 100 Spanish companies distributing internationally. As a result it is concluded that there are economies of scale related to the size of the carrier (the ship) and its capacity to absorb the variability in demand. This potential increases with the cargo value. Additionally, a framework of supply/distribution chains is provided which can help to identify potential customers/sectors and the feasibility of new potential shipping lines. The value of this paper resides in its approach (strategic, instead of operational/tactical), and the solid groundwork point provided for future researchers.     

Expansion of a Controlled Parking Zone (CPZ) and its Influence on Modal Split: The Case of Edinburgh

Abstract

This article considers the inter-relationship between on-street parking and choice of mode for journeys to work in the Scottish city of Edinburgh. This city is typical of many in that its centre has significant on-street parking controls but, beyond a radius of 1 to 1 1/2 miles (1.5 to 2.5?km) from the centre, there are no controls and commuter parking on-street is commonplace. The article reviews the relevant literature, and then considers the results of a survey undertaken of Edinburgh city centre employees in order to ascertain their parking habits and likely response to the extension of existing on-street parking controls. The article concludes that the results are transferable to other cities but that the scale of the impacts in each will be related to site specific factors, particularly the demand for residential parking space on-street in areas close to the city centre.     

考虑交叉口影响的城市路网信号优化设计问题研究

基于城市路网交通间断流特性,本文将微观层面的信号交叉口延误计算方法引入宏观层面的平衡网络信号优化设计问题,构建了一个中观层面的城市路网交叉口信号优化设计双层规划模型,设计了基于遗传操作的优化算法。通过路网算例对模型及算法进行测试,并通过与微观、宏观层面的两种信号优化配时方法进行比较,验证所提出模型的优越性。     

基于动刚度和模态应变能的某车NVH性能改善研究

本文通过创建某车的白车身模型和带内饰车身模型,进行车身噪声传递函数分析,并结合车身的模态应变能分布情况和动刚度分析结果,查找并确定导致车内噪音较大的原因,并提出了几种优化方案,采用CAE方法选择最佳方案,经试验验证,最终改善车身的NVH性能。     

基于有限元分析的客车振动试验研究

在ANSYS中建立客车骨架的有限元板梁单元模型,并通过电测试验验证;利用ANSYS软件对客车整车进行有限元模态分析,谐响应验证分析;最后通过实车行驶振动试验,验证模态分析和谐响应分析的正确性。     

两款白车身试验模态分析与比较

为提高某新型卡车白车身振动特性,改善车身的耐久性与舒适性,通过具体模态试验,获得并分析了该轻卡白车身模态试验数据。根据与该车型相匹配的部件振动参数,并参考相同平台的某型客车振动参数,提出了该新型卡车白车身改进方案。同时介绍了模态试验系统的组成和流程,探讨了试验测系统、模态数据可靠性检验的一般方法。     

汽车车架OMA实验模态分析

模态参数辨识是系统辨识的一部分,通过模态参数的辨识,可以了解系统或结构的动力学特性,这些动力特性可作为结构有限元模型修正、故障诊断、结构实时监测的评定标准和基础。本文以212车架为研究对象,综合考虑悬挂条件,激励方式及布点位置对实验结果的影响,对其进行模态试验。通过使用ICATS软件对采集到的数据进行时域内的工作模态分析,然后得到模态参数。