Managing transportation during highway reconstruction: A recommended process

Major highway reconstruction can cause significant disruptions to existing travel patterns and economic activity. Reducing these impacts on travelers, shippers, businesses and residents requires that innovative and effective transportation management actions be developed and implemented. This paper reports the major findings and recommendations of a research study on managing transportation during highway, reconstruction. The primary objectives of the study were

Joint development at transit stations in the United States

Joint development, as the term is generally used in connection with transit systems in the United States, is real estate development that is closely linked to public transportation services and station facilities, and takes advantage of the market and locational advantages provided by them. Research conducted by LEK Associates for the Urban Mass Transportation Administration (UMTA) suggests that, in addition to helping shape urban growth and land development, joint development is also a surprisingly effective means of increasing transit system ridership and farebox revenues, as well as a source of increasingly significant revenues from the sale or lease of air rights.The completion of nine joint development projects in as many different cities, started under the former Urban Initiatives Program, for example, net additional annual ridership might reach 12000000 one-way trips. Net additional annual farebox revenues might reach over $9000000. This added revenue would be sufficient to repay the $62 million combined UMTA/transit operator investment in the nine projects, exclusive of the costs of the basic transit system improvements around which the projects are planned, in less than six years.Among transit authority-administered joint development programs examined in a separate study, the Washington Metropolitan Area Transit Authority (WMATA) has had the most success in generating significant value capture income. For example, the cumulative revenue realized by WMATA from just six joint development projects in the Washington, DC region, through September 1983 exceeded $ 6.9 million. Projections through fiscal year 1986 indicate cumulative revenues approximating $ 28 million will be received from developer leases.     

Urban transportation modeling: The discussion continues

This article is a response to John Polak's article, entitled, A Comment on Supernak's Critique of Transport Modeling, published elsewhere in this issue of TRANSPORTATION. It offers necessary clarifications to the issues discussed in an earlier article in this journal (Supernak, 1983). It also responds to the philosophical issues discussed in Polak's article, such as the nature of transport phenomena, and the role, form and methodology of transport modeling.     

Regional impacts of new transport infrastructure: a multisectoral potentials approach

This is the second of two background papers sponsored for the Symposium by the Administrative Commission for the north of the Netherlands. Its purpose is to provide an indication of the effects of the proposed high speed rail line between Amsterdam, Groningen and Hamburg on employment in the corridor. The authors first review the techniques of forecasting these effects discussed in the literature. The potentials approach is adopted for their analysis, the mathematics and underlying assumptions of which are presented. Finally, this model is run to provide an estimate of the impact on regional employment of three variants of the proposed rail line.     

The design of bus route systems — An interactive location-allocation approach

An interactive modelling approach is developed to solve the practical problem of bus route network design. Possible bus routes are identified with facilities which can be located. Zones or pairs of zones in the urban area are identified with customers who will be allocated to the established facilities. It is shown that the classical Set Covering Problem is useful under the assumption of fixed demand; the Simple Plant Location Problem is effective under the assumption of demand which is sensitive to the level of bus service provided.     

人类仿真技术在铁路系统中的应用

摘要：对应用于铁路人机工程学的人类仿真方法进行了总结,即一种仿真器是采用虚拟现实技术来模拟环境,例如驾驶仿真器、乘坐舒适度仿真器、铁路车站仿真器等。另一类仿真器则采用计算机仿真技术来评价列车司机工作时承受的精神负担、列车碰撞引起的旅客运动方式及损伤等。     

25Hz相敏轨道电路自动调压系统研究

根据铁路现场对轨道电路检修要求和《铁路信号维修规则技术标准I》中对25Hz相敏轨道电路轨道电压的规定,总结出铁路现场对自动调压系统的需求,并结合目前单片机和传感器技术的发展,对25Hz相敏轨道电路自动调压系统进行了研究。     

地铁列车运行引起建筑物二次辐射噪声执行标准探讨

分析我国城市轨道交通环境影响评价中,关于列车运行引起的建筑物二次辐射噪声参考标准的适宜性,并根据二次辐射噪声原理和定义,探讨了城市轨道交通列车运行引起的建筑物二次辐射噪声宜执行的相关标准及评价量。     

Micro-Grinding Performance of Hard-Brittle Chip Materials in Precision Micro-Grinding Microgroove

The micro-structure on hard-brittle chip materials (HBCMs) surface can produce predominant functions and features. The micro-grinding with diamond wheel micro-tip is an efficient method to machine microstructure on HBCMs. However, different HBCMs and crystal orientation may have a significant influence on the micro-grinding performance. In this paper, the micro-grinding performance along different crystal orientation of HBCMs is investigated. First, a dressed 600^# diamond grinding wheel is used to micro-grind micro-structure on HBCMs. Then, the experiment of micro-grinding force test is completed. Finally, the quality of microgroove, the grinding ratio and the micro-grinding force are investigated and they are related to the crystal orientation of HBCMs. It is shown that the stronger resistance to the micro-crack propagation has the best quality of microgroove and the smallest grinding ratio. Moreover, the hardest single-crystal SiC has the best machinability and the micro-grinding force is 38.9%, 10.8% and 46.8% less than the one of sapphire, single-crystal Si and quartz glass, respectively. The direction to micro-grind easily is the crystal orientation 〈10\(\overline 1 \)0〉 for single-crystal SiC and sapphire. In addition, the micro-grinding force increases with the increase of the micro-grinding depth and feed rate and decreases with the increase of the grinding wheel speed.