Real-time merging traffic control for throughput maximization at motorway work zones

Work zones on motorways necessitate the drop of one or more lanes which may lead to significant reduction of traffic flow capacity and efficiency, traffic flow disruptions, congestion creation, and increased accident risk. Real-time traffic control by use of green–red traffic signals at the motorway mainstream is proposed in order to achieve safer merging of vehicles entering the work zone and, at the same time, maximize throughput and reduce travel delays. A significant issue that had been neglected in previous research is the investigation of the impact of distance between the merge area and the traffic lights so as to achieve, in combination with the employed real-time traffic control strategy, the most efficient merging of vehicles. The control strategy applied for real-time signal operation is based on an ALINEA-like proportional–integral (PI-type) feedback regulator. In order to achieve maximum performance of the control strategy, some calibration of the regulator’s parameters may be necessary. The calibration is first conducted manually, via a typical trial-and-error procedure. In an additional investigation, the recently proposed learning/adaptive fine-tuning (AFT) algorithm is employed in order to automatically fine-tune the regulator parameters. Experiments conducted with a microscopic simulator for a hypothetical work zone infrastructure, demonstrate the potential high benefits of the control scheme.     

Effectiveness of graphic-aided portable changeable message signs in reducing vehicle speeds in highway work zones

Portable changeable message signs (PCMSs) have been employed in highway work zones as a temporary traffic control device for decades in the United States. Results of previous research showed that the traditional text-based PCMS had several limitations, such as having a short range of legibility and being difficult to read by elderly and non-English-speaking drivers. A few simulation studies indicated that using graphic-aided PCMSs could likely overcome these limitations. This paper presents the results of field experiments that were conducted to determine the effectiveness of graphic-aided PCMS in reducing vehicle speeds in the upstream of highway work zones. In field experiment Phase I, a full-matrix PCMS was programmed to display a work zone graphic and a flagger graphic, which were similar to the W21-1 sign and W20-7 sign, respectively, specified by the Manual on Uniform Traffic Control Devices. In field experiment Phase II, the PCMS was programmed to display two alternative work zone graphics along with the original work zone graphic. 1115 and 1600 valid vehicle speed data were collected during field experiments Phase I and Phase II, respectively. The results of data analysis suggested that graphic-aided PCMSs reduced mean vehicle speeds between 13% and 17% in the upstream of a work zone. This study provided valuable knowledge to government agencies and the transportation industry on how to regulate and implement graphic-aided PCMS in highway work zones.     

关于铁路建设工程验工计价的探讨

铁路建设工程验工计价,是建设单位进行承发包合同管理和控制工程投资的关键环节.此文在介绍国家和行业有关验工计价规定的前提下,对以往和当前建设工程验工计价现状及存在的几个主要问题进行分析.针对存在的主要问题,就如何规范验工计价进行探讨,提出可采取的几项措施.并就采用计算机技术进行验工计价提出思路.     

浅析当前建设形势下监理驻地办的工作思路

就当前建设形势下监理驻地办的工作思路进行了论述。     

论统计工作在高校人事管理中的作用

本文首先阐述了统计工作在高校人事管理中的意义,然后剖析了当前高校人事管理工作中统计作用降低的原因,并从提高认识、提高工作人员素质、完善人事统计指标和加强人事统计信息化建设等方面,提出了相关对策和建议。     

桥涵工程变更设计原因分析

通过对某铁路工程桥涵进行变更设计统计分析,明确产生变更的原因,并采取相应的对策,使设计变更降低到最低限度,确保工程质量,控制工期、费用达到预期目的。     

服装行业工人健康调查

服装行业的职业卫生正在引起人们的重视，现代化服装生产采取流水作业方式，由此造成了精神紧张和强迫体位等职业卫生问题影响了工人的健康。对北京市几个大型服装厂３５６名工人进行的体检结果表明，坐位工人主要是腰部疼痛、肩部酸痛及背部疼痛，站位作业主要是腰部疼痛、下肢胀痛及肩部酸痛，与对照组比较差异有显著性或高度显著性。根据本调查结果，神经衰弱症候群，肩、背、腰部酸痛，眼疲劳不适是服装作业工人的主要症状。     

强化设计变更管理控制铁路工程投资

设计变更是造成工程概算突破的重要环节。如何有效地控制投资，是工程项目实施过程中的一个重点和难点。笔结合现场配合施工的实际经验，从不同方面论述了强化设计变更管理、控制工程投资的有效方法和途径。     

执法路上 别忘了保护好自己——道路交通事故出警效率与安全“博弈”

随着我国道路交通事故致因和形态日渐复杂化和多样化,事故处理和救援对公安交管部门出警效率与安全提出了严峻考验。现有交通事故出警反应机制主要对出警任务进行了界定,缺乏影响安全的出警决策和指挥调度的内容,并且出警指挥平台和民警科技装备应用水平的限制,进一步影响了事故出警效率与安全。针对事故出警效率和安全问题,从法律制度、出警机制和出警智能化等层面提出了平衡策略,对预防事故现场二次事故和保障民警安全具有重要意义。     

程序框图的自动生成交互系统

运用数据库和计算机高级编程语言设计开发了程序框图的自动生成交互系统,实现程序框图的自动生成和实时修改,使程序框图的生成效率显著提高,具有很好的实用价值.