出海路祖山至马蹄岭段路况调查

出海路祖山至马蹄岭段主要为水泥混凝土路面,路段经过12年的运营各种病害发展迅速.2012年4月通过咨询、调查、收集、测试等手段,对该路段气象水文、交通组成、养护维修历史、路面结构、路面检测指标、路面病害种类、桥涵情况进行了详细调查,获得了真实可靠的资料,为大修方案的确定提供了依据.     

The design of a terminal for dangerous goods

This paper aims at examining the possibility of setting up a model terminal for the transportation of dangerous goods. It should be designed in such a manner that its use would be possible for any kind of transportation.

This consideration has been prompted by the interface between transportation planning and technology, as well as by the tendency for harmonizing international recommendations pertaining to the transportation and handling of dangerous goods, especially during the last decades where unified transport has gained ground due to the advantages provided for the safe consignment of dangerous cargoes.

Since the large increase in terminal productivity is due to the heavy investments that were effected in terminal installations and to the modernization of the administration‐management of terminals, a mathematical simulation has been adopted to assist the determination of the capacity of a terminal for dangerous goods.

It is evident that different criteria and various assumptions have been taken into account in order to facilitate a deeper analysis, without ignoring the contribution of dangerous goods to the socio‐economic development.

From the outset of the study, it was already clear that the said process will make it possible to present—as a model—a simple but well defined situation for the purpose of drawing useful conclusions.     

Alternative fuels for transportation

The alternatives to the oil based fuels for transportation are considered and analysed. These are the synthetic fuels, made from coal, the liquid petroleum gases of propane and butane, compressed natural gas and methanol. The problems associated with the use of electric vehicles are discussed; the main problem being that of range.

The possible use of hydrogen as a fuel is analysed in some detail. Since its supply can be tied directly to nuclear energy sources, rather than hydrocarbon feed stocks, it could be an alternative in the long term. The main problems of the storage of hydrogen on the vehicle and of its propensity to “back‐fire” into the engine intake are discussed. The first can be ameliorated and the second eliminated by dual fuelling; with petrol. It is advocated that the on‐board storage of hydrogen be by the use of hydrides for private cars. However, it is expected that it may be as liquid hydrogen for some forms of transport and will certainly be in this form for aircraft.     

The use of demand correlation in the modeling of air carrier departure delays as first‐order autoregressive random processes

A method for modeling air carrier departure delays at commercial‐service airports as autoregressive random processes is presented. This method employs the correlation of a priori demand data to significantly reduce prediction error in the optimal least‐squares estimator for additive white noise. The reduction factor of the prediction error is demonstrated to be on the order of 10² over that of the unbiased estimator. Copyright © 2011 John Wiley & Sons, Ltd.     

Privacy protection method for fine-grained urban traffic modeling using mobile sensors

With the ubiquitous nature of mobile sensing technologies, privacy issues are becoming increasingly important, and need to be carefully addressed. Data needs for transportation modeling and privacy protection should be deliberately balanced for different applications. This paper focuses on developing privacy mechanisms that would simultaneously satisfy privacy protection and data needs for fine-grained urban traffic modeling applications using mobile sensors. To accomplish this, a virtual trip lines (VTLs) zone-based system and related filtering approaches are developed. Traffic-knowledge-based adversary models are proposed and tested to evaluate the effectiveness of such a privacy protection system by making privacy attacks. The results show that in addition to ensuring an acceptable level of privacy, the released datasets from the privacy-enhancing system can also be applied to urban traffic modeling with satisfactory results. Albeit application-specific, such a “Privacy-by-Design” approach would hopefully shed some light on other transportation applications using mobile sensors.     

Optimization of transport investment and pricing policies: the role of transport pricing in network design

This paper investigates the role of transport pricing in network design and describes two facts about flow pattern in a transportation system. The first, illustrated by an example of Braess paradox, is that adding a new link to the network does not necessarily minimize the total travel time. The second is that introducing of appropriate toll pricing may reduce not only the total network time but also the travel time for each individual traveller. It follows with the investigations of different system objectives and different pricing policies (only toll pricing and distance‐based pricing are considered), and shows how they affect the system performance and flow pattern. Lastly, a systematic optimization process is proposed for integrated planning of transport network and pricing policies.     

高速公路大修工程施工区安全与交通组织研究

进行大修的高速公路,大多是所在区域的运输干道和交通骨架,交通量往往很大,交通环境复杂,如果对交通组织研究得不够,会导致施工时交通组织混乱,严重影响施进度和施工区的安全,还会造成长时间交通拥堵等被动局面.对高速公路大修施工路段事故原因、交通组织方案和交通分流的分析,对于确保施工的顺利实施以及驾驶员和施工人员安全具有重要意义.     

大型机场地面集疏运需求预测方法研究

机场地面集疏运系统是机场发展的重要支撑，交通需求预测是进行机场集疏运交通规划的前提。笔者以四阶段预测的基本原理为基础，结合机场集疏运需求特点，对预测的整体思路、方法、步骤和内容等进行详细分析，优化调整出行分布、方式划分预测模型，并以南京禄口国际机场为实例进行了预测。研究成果对国内同类大型机场的集疏运需求预测具有借鉴和参考价值。