Effect of road width and traffic volume on vehicular interactions in heterogeneous traffic

Highway traffic flow phenomena involve several complex and stochastic variables with high interdependencies. The variations in roadway, traffic and environmental factors influence the traffic flow quality significantly. Capacity analysis of road sections under different traffic and geometric conditions need to quantify the vehicles of widely varying characteristics to a common and universally acceptable unit. Passenger car unit (PCU) is the universally adopted unit of traffic volume, keeping the passenger car as the ‘standard vehicle’ with reference to its static and dynamic characteristics; other vehicles are expressed to its equivalent number in terms of PCUs. The studies carried out in this aspect represent the dynamic nature of impedance caused by a vehicle while moving through a traffic stream. The PCU values recommended by the Highway Capacity Manual are widely applied in many countries; however, their applicability is highly under debate because of the variations in prevailing local traffic conditions. There are several factors that influence the PCU values such as traffic, roadway, vehicle, environmental and control conditions, etc. Apart from vehicular characteristics, the other two major factors that influence the PCU of vehicles are the following: (i) road width and (ii) traffic volume. In this study, estimation of PCU values for the different types of vehicles of a highly heterogeneous traffic on 7.5‐ and 11.0‐m‐wide roads, using micro‐simulation technique, has been dealt with. It has been found that the PCU value of a vehicle type varies significantly with variation in road width and traffic volume. The results of the study indicate that the PCU values are significantly influenced by the said two factors. Copyright © 2012 John Wiley & Sons, Ltd.     

Transport deregulation and the economy wide implications of the wheeler‐Gilmour hypothesis

This paper focuses on the effects of deregulation of motor carriers in Australia. It is particularly concerned with the implications of regulatory reform beyond the transport sector and uses a general equilibrium approach to examine the economy wide effects of deregulation. Among other things the paper shows that the effects of deregulation are not evenly distributed across all types of industries. Furthermore it concludes that the magnitude of the effects from deregulation in any given industry is not necessarily correlated with the share of total costs devoted to the purchase of transportation services.

     

Locating charging infrastructure for electric buses in Stockholm

Charging infrastructure requirements are being largely debated in the context of urban energy planning for transport electrification. As electric vehicles are gaining momentum, the issue of locating and securing the availability, efficiency and effectiveness of charging infrastructure becomes a complex question that needs to be addressed. This paper presents the structure and application of a model developed for optimizing the distribution of charging infrastructure for electric buses in the urban context, and tests the model for the bus network of Stockholm. The major public bus transport hubs connecting to the train and subway system show the highest concentration of locations chosen by the model for charging station installation. The costs estimated are within an expected range when comparing to the annual bus public transport costs in Stockholm. The model could be adapted for various urban contexts to promptly assist in the transition to fossil-free bus transport. The total costs for the operation of a partially electrified bus system in both optimization cases considered (cost and energy) differ only marginally from the costs for a 100% biodiesel system. This indicates that lower fuel costs for electric buses can balance the high investment costs incurred in building charging infrastructure, while achieving a reduction of up to 51% in emissions and up to 34% in energy use in the bus fleet.     

Dedication to Peter Douglas (August 22, 1942–April 1, 2012)

Ecosystem management has been deemed a promising approach to environmental management in many settings. The ecosystem approach promises improved use of scientific information, better management coordination, and more meaningful public participation in environmental decision making. Yet, there is little evidence for how well ecosystem management efforts actually achieve their goals. This article presents an in‐depth analysis of one ecosystem management effort, the Albemarle‐Pamlico Estuarine Study (APES), which was part of the National Estuary Program. The APES failed to meet the objectives of ecosystem management in several visible ways. However, this case study reveals that the APES also had many positive results that were less visible to participants and observers. The performance of the APES is explained with reference to seven paradoxes inherent in the concept of ecosystem management. These findings have implications for appropriate expectations and evaluation of other ecosystem management efforts.     

面对税收政策差异如何进行跨地区施工纳税管理与策划

建筑企业为了寻求企业发展,都在不断地进行跨地区作业,各地税收政策直接影响了施工企业的纳税成本。为此,建筑企业应加强内部税务管理、进行税收策划、降低纳税成本、规避税务风险、增强企业竞争能力。本文主要是以企业价值最大化为目标,根据施工企业的特点,利用施工地点税收征管差异,合理、合法避税,以达到降低企业税务风险目的。     

不利天气高速公路路况车载采集系统研究

分析了不利天气下道路安全状况评估参数及其影响因素，确定了车载路况采集系统的功能，设计了由道路能见度检测、道路环境温湿度检测、路面状况识别、路面微观形貌检测、路况数据定位与路况数据无线传输6个子系统以及检测车、电源系统等组成的路况检测系统，分析了系统设计中的一些关键技术。     

超限运输的成因及治理措施

超限运输是目前公路运输领域一个普遍存在的现象，为了更好地治理超限运输．从法律意识、危害意识、管理形式不合理等方面对超限运输的成因加以分析，并在此基础上，提出一些治理超限运输的建议措施。     

区域性道路运输服务体系构建的初步思考

区域性道路运输服务体系的建设对于区域经济的发展有重要的意义。文章探索了构建区域道路服务体系的必要性、战略思考、措施以及政府应发挥的作用。     

铁路重点运输企业水损耗因素及节水措施研究

通过对铁路机务段、车辆段等重点运输企业用水的调查,找出了水损耗的主要因素。在此基础上提出了以下建议：（1）强化节水奖励力度：在铁路局及站段层面完善并落实专门的节水奖励政策,用水指标应根据工作量、定员及单位实际合理核定,节约部分全部用于基层职工的奖励。（2）站段所有用水终端均应安装计量水表（三级表）,并建立用水台帐。     

关于渤海湾危险货物滚装运输的探讨

文中分析了渤海湾危险货物滚装运输发展的现状，论述了制约危险货物滚装运输的主要因素，提出了相应的改进建议和加强监督管理的措施