A model of the vicious cycle of a bus line

It has been frequently noted that in a non-regulated environment the development of public transport service is self-adjusting: Faced with decreasing demand, operators will tend to reduce service to cut costs, resulting in a decrease in the level-of-service, which then triggers a further drop in demand. The opposite may also occur: high demand will induce the operator to increase supply, e.g. through an increase in frequency, which results in a higher level-of-service and a subsequent increase in passenger numbers, triggering another round of service improvements. This paper adds to the literature by presenting an analytic model for analyzing these phenomena that we call vicious and virtuous cycles. Based on field data regarding passengers’ variation in willingness-to-wait for a public transport service, we investigate the dynamics of the line service and show how the emergence of a vicious or virtuous cycle depends on the total number of potential passengers, the share of captive riders, and bus capacity. The paper ends with a discussion of the implications of the findings for the planning of public transport services.     

快速公交系统评价指标体系构建及案例分析

本文在构建BRT系统评价指标体系的基础上,以北京已建的三条BRT线路为评价案例,重点分析和总结了BRT系统建设和运营中的经验,望能提供有益参考.     

客车前风挡玻璃粘接力计算分析

随着客车技术的渐渐成熟,人们对客车的安全系数有了越来越高的要求。尤其对于在公路上高速行驶的客车来说,安全因素是考虑的首要因素。以下针对客车前风挡玻璃在高速行驶,紧急制动情况下受力状态加以阐明。     

通道式客车瞬间转向失控成因分析

本文从转向运动学的角度,对通道式客车发生瞬间转向失控的形成原因进行了分析,并提出了防止的方法与措施.     

公交场站利用地热能供暖及制冷的实践与分析

对北京公交集团老旧公交场站办公区及生活区供暖制冷方式进行改造,将原冬季燃油锅炉供暖和夏季分体式空調制冷方式改造为地埋管地源热泵系统,为场站的办公区及生活区冬季供暖和夏季制冷提供更好的方式,并达到节能减排的目的.     

公交车辆班次供应智能监管技术浅析

上海市城市交通运输管理处已建成一套基于GPS定位技术的公交车辆营运监管系统,可以对线路车辆班次供应情况进行智能化监管,该系统的数据主要由车载GPS终端分发获取,由于GPS技术本身的局限性,使得车辆在首末站数据包丢失,无法做到准确统计.本文提出远距离射频识别技术与GPS技术相结合的办法,可以使公交车辆经过首末站的识别率达...     

济南市BRT车辆类型对比研究

优先发展公共交通是缓解拥堵的重要手段。快速公交（BRT）作为济南中运量系统的制式,其运输工具的性能对乘客出行时间、企业的运营效益具有重要意义。因此,对天然气车和现代无轨电车两种绿色公共交通车辆的性能进行介绍,从技术、经济、环境、社会影响和实施可行性几个方面进行对比,最后选择出合适的车辆类型作为济南市BRT的运载工具。     

基于FPGA液力传动内燃机车CAN通讯单元设计

开发设计了一种基于FPGA,能够对内燃机车发动机和变速箱的控制系统的行车数据、故障数据等稳定传输的CAN总线通讯电路.所设计的接口电路基于SAE J1939协议,由FPGA微处理器、CAN控制器等硬件电路以及软件设计组成.此方案可以大大节省CPU的开销,提高系统整体的工作效率,满足系统的高实时性和稳定性要求.     

Modular route bus design – A method of meeting transport operation and vehicle manufacturing requirements

This research examines the problem of route bus specification and vehicle manufacturability. In order for bus operators to provide transport services, a range of vehicle configurations must be available from bus manufacturers, generating variety which has a negative impact on the manufacturing process. Larger part inventories, uncontrolled labour tasks and more troublesome maintenance are known impacts of this variety. This research identifies the functional necessities in route bus interior design and reduces the problems in bus manufacture and operation caused by specification diversity by proposing a modularised system of bus design. In particular, it makes recommendations as to how bus configuration should be carried out, ensuring an optimum mix of operational and manufacturing needs:

• 1.Determine user needs before the bus specification process.
• 2.Designs to be developed by the manufacturer in response to user needs.
• 3.This design should be standardised where possible, as suggested by the user needs.
• 4.Where user needs dictate product variations, apply a mass customisation approach to accommodate these needs.

The recommendations are communicated in design proposals for a modular bus interior, demonstrated by four cases designed to meet the present status quo of bus interior design and predictions for the future of the field.     

电容补偿装置投切过电压的防护措施研究

对采用阻尼与限压措施消除电容补偿装置投切过电压可能存在的危害进行了理论与仿真分析,并指出：投入过电压的防护主要应依靠装置本身的绝缘结构能力来实现,阻尼限压等保护措施对之效果不明显;截流过电压对开断时电弧重燃起重要的助推作用,电弧重燃会产生破坏力极大的过电压,利用高阻值阻尼电阻可消除截流过电压对电弧重燃的影响。