城市绿色出行内涵和评价指标体系框架研究

绿色出行发展的根本目的是为了实现城市交通可持续发展,实现出行"安全、畅通、高效、舒适、环保、节能",从而实现社会、经济、交通和环境的协调发展。本文通过对绿色出行的概念、内涵、特征和实现途径等相关理论进行解读,确定绿色出行系统的主要构成;采用计划行为理论、交通需求管理理论等多视角,对影响和制约城市绿色出行发展的关键因素进行分析和识别,并研究提出围绕保障能力、基础设施、运输装备、运营服务等方面的绿色出行评价指标体系框架。     

浅谈高速公路美丽服务区的建设思路

构建美丽服务区应以绿色、低碳、循环发展、智慧化以及满足出行用户的多元化需求为出发点,从节能建筑、清洁能源应用、污水处理及循环利用、固废处理及循环利用、生态服务、人性化服务等环节综合考虑,从而提升服务区整体形象,加强服务区设施的人性化和标准化服务管理。本文从高速公路美丽服务区构建的必要性入手,探讨了从节能建筑、清洁能源应用、污水处理及循环利用、固废处理及循环利用、生态服务、人性化服务等方面构建美丽服务区。     

Chemical characteristics of the surface soil,herbaceous cover and organic layer of a compacted skid road in a fir (Abies bornmulleriana Mattf.) forest

This study looks at the impacts of timber skidding in a pure fir plantation forest. It compares properties of herbaceous cover, organic layer and surface soil on the skid road and on adjacent undisturbed area. N, P, K, Ca, Mg, Na, Fe, Zn, Mn and Cu are quantified and the mass of herbaceous cover and organic layer, and sand, silt, clay rates, bulk density, compaction and pH of soils were assessed. Both the herbaceous cover and organic layer mass on the skid road were significantly lower than the undisturbed area. The soil of the skid road also had higher bulk density and compaction, and lower organic carbon rates producing much denser and compacted soils. Only P concentration in herbaceous cover samples from skid road was significantly higher, while Ca and Mg contents were considerably lower than undisturbed area. There were no significantly differences in N, K, Na, Fe, Zn, Cu and Mn concentrations of herbaceous cover. Compared to the undisturbed area, the organic layer of the skid road had particularly low K, Na, Fe, Zn, Cu and Mn contents. At 0–5 cm soil depth, P and Fe contents were significantly lower than for undisturbed area but there were no major differences at depth of 5–10 cm.     

青藏高原冻土地区公路施工中的环境保护技术

本文以中国一带一路重点项目西藏自治区国道109线那曲至拉萨公路改建工程为依托,研究了高原冻土地区公路施工中的环境保护与水土保持技术。根据设计资料、施工现场调查和主要施工方法,总结出10项环境保护与水土保持的重要因素;在可持续发展理念和绿色生态理念的公路施工背景下,针对高原冻土地区的植被保护与恢复问题,在施工场地及临建、取土场、弃土场以及路基边坡采用了原有植被草皮表土回填法;针对泥浆、污水、噪声、扬尘排放等引起的水环境、声环境及空气环境保护问题,制定了有效的防护措施,并取得显著效果。     

高速公路机电工程监理流程

设备众多、专业性强,施工界面交叉多,工程量大且工期短,是高速公路机电工程的特点。为保证机电工程质量、进度、费用、环保、资料等方面符合合同及规范要求,探讨了高速公路机电工程监理的重点难点,并提出监理工作程序及监理控制要点。     

Life cycle assessment of pavement: Methodology and case study

A life cycle assessment model is built to estimate the environmental implications of pavements using material, distribution, construction, congestion, usage, and end of life modules. A case study of three overlay systems, Portland cement concrete overlay, hot mixture asphalt overlay, and crack, seat, and overlay, is presented. The case leads to the following conclusions. It is reasonable to expect less environmental burdens from the Portland cement concrete and crack, seat, and overlay options as opposed to hot mixture asphalt while although the results have a high degree uncertainties. The material, congestion, and particularly usage modules contribute most to energy consumption and air pollutant. Traffic related energy consumption and greenhouse gases are sensitive to traffic growth and fuel economy improvement. Uncertainties exist in the usage module, especially for the pavement structure effect.     

Representing and estimating interactions between activities in a need-based model of activity generation

Although several activity-based models made the transition to practice in recent years, modeling dynamic activity generation and especially, the mechanisms underlying activity generation are not well incorporated in the current activity-based models. For instance, current models assume that activities are independent, but to the extent that different activities fulfill the same underlying needs and act as partial substitutes, their interactions/dependencies should be taken into account. For example, recreational, leisure, and social activities tend to be partly substitutable since they satisfy a common need of relaxation, and when undertaken together with others, social needs will be satisfied as well. This paper describes the parameter estimation of a need-based activity generation model, which includes the representation of possible interaction effects between activities. A survey was carried out to collect activity data for a typical week and a specific day among a sample of individuals. The diary data contain detailed information on activity history and future planning. Estimation of the model involves a range of shopping, social, leisure, and sports activities, as dependent variables, and socioeconomic, day preference, and interaction variables, as explanatory variables. The results show that several person, household, and dwelling attributes influence activity-episode timing decisions in a longitudinal time frame and, thus, the frequency and day choice of conducting the social, leisure, and sports activities. Furthermore, interactions were found in the sense that several activities influence the need for other activities and some activities affect the utility of conducting another activity on the same day.     

北欧公路印象与启示

以人为本、尊重自然、适用完善是北欧公路的鲜明特点。本文介绍了北欧公路在总体设计、路线、路基路面、排水、桥遂、交通工程及服务设施、运营管理等方面的具体做法,并结合我国公路的现状提出了一些思路。     

Are we ready to embrace connected and self-driving vehicles? A case study of Texans

While connected, highly automated, and autonomous vehicles (CAVs) will eventually hit the roads, their success and market penetration rates depend largely on public opinions regarding benefits, concerns, and adoption of these technologies. Additionally, the introduction of these technologies is accompanied by uncertainties in their effects on the carsharing market and land use patterns, and raises the need for tolling policies to appease the travel demand induced due to the increased convenience. To these ends, this study surveyed 1088 respondents across Texas to understand their opinions about smart vehicle technologies and related decisions. The key summary statistics indicate that Texans are willing to pay (WTP) $2910, $4607, $7589, and $127 for Level 2, Level 3, and Level 4 automation and connectivity, respectively, on average. Moreover, affordability and equipment failure are Texans’ top two concerns regarding AVs. This study also estimates interval regression and ordered probit models to understand the multivariate correlation between explanatory variables, such as demographics, built-environment attributes, travel patterns, and crash histories, and response variables, including willingness to pay for CAV technologies, adoption rates of shared AVs at different pricing points, home location shift decisions, adoption timing of automation technologies, and opinions about various tolling policies. The practically significant relationships indicate that more experienced licensed drivers and older people associate lower WTP values with all new vehicle technologies. Such parameter estimates help not only in forecasting long-term adoption of CAV technologies, but also help transportation planners in understanding the characteristics of regions with high or low future-year CAV adoption levels, and subsequently, develop smart strategies in respective regions.     

公路山岭隧道衬砌结构补漏技术研究进展

为全面了解公路山岭隧道衬砌结构补漏技术的最新研究进展,文章通过对既有公路山岭隧道的调查和统计,结合大量的文献资料,从防排水设计、材料和施工等方面分析了渗漏现象的本质,明确了隧道抗渗防漏的薄弱部位和保证补漏效果的关键环节;从衬砌混凝土、施工缝、变形缝和活裂缝等方面,介绍了当前国内外补漏技术的最新研究成果(包括补漏涂材、构造补漏和施工工艺等);并探讨了当前隧道补漏技术存在的问题和发展的新趋势。     

Well-to-wheel costs,primary energy demand,and greenhouse gas emissions for the production and operation of conventional and alternative vehicles

This study provides a comprehensive comparison of well-to-wheel (WTW) energy demand, WTW GHG emissions, and costs for conventional ICE and alternative passenger car powertrains, including full electric, hybrid, and fuel cell powertrains. Vehicle production, operation, maintenance, and disposal are considered, along with a range of hydrogen production processes, electricity mixes, ICE fuels, and battery types. Results are determined based on a reference vehicle, powertrain efficiencies, life cycle inventory data, and cost estimations. Powertrain performance is measured against a gasoline ICE vehicle. Energy carrier and battery production are found to be the largest contributors to WTW energy demand, GHG emissions, and costs; however, electric powertrain performance is highly sensitive to battery specific energy. ICE and full hybrid vehicles using alternative fuels to gasoline, and fuel cell vehicles using natural gas hydrogen production pathways, are the only powertrains which demonstrate reductions in all three evaluation categories simultaneously (i.e., WTW energy demand, emissions, and costs). Overall, however, WTW emission reductions depend more on the energy carrier production pathway than on the powertrain; hence, alternative energy carriers to gasoline for an ICE-based fleet (including hybrids) should be emphasized from a policy perspective in the short-term. This will ease the transition towards a low-emission fleet in Switzerland.     

A cognitive framework to plan for the future of transportation

ABSTRACT

Automated, connected, electrified, and shared mobility will be cornerstones of the transportation future. Research to quantify the potential benefits and drawbacks of practice, and to identify barriers to adoption, is the first step in any strategic plan for their adoption. However, uncertainties, complexity, interdependence, and the multidisciplinary nature of emerging transportation technologies make it difficult to organize and identify focused research. The contribution of this work is a cognitive framework to help planners and policymakers organize broad topics, reveal challenges, discover ideas for solutions, quantify potential impacts, and identify implications to guide preparation strategies. The authors provide example cognitive frameworks for connected, automated, and electrified vehicles.     

沥青混凝土路面平整度差的成因及对策研究

结合G205、G312等沥青路面不同程度出现的沉陷、接缝台阶、波浪、车辙、桥涵与路面接茬不平、跳车等路面不平整现象,分析、探讨造成沥青路面平整度差的路基、桥涵、路面基层施工方面、材料方面以及路面摊铺、碾压等主要原因,并提出相应对策措施。     

Fuel economy,cost, and greenhouse gas results for alternative fuel vehicles in 2011

This paper presents in-service data collected from over 300 alternative fuel vehicles and over 80 fueling stations to help fleets determine what types of applications and alternative fuels may help them reduce their environmental impacts and fuel costs. The data were compiled in 2011 by over 30 organizations in New York State using a wide variety of commercial vehicle types and technologies. Fuel economy, incremental vehicle purchase cost, fueling station purchase cost, greenhouse gas reductions, and fuel cost savings data clarifies the performance of alternative fuel vehicles and fuel stations. Data were collected from a range of vehicle types, including school buses, delivery trucks, utility vans, street sweepers, snow plows, street pavers, bucket trucks, paratransit vans, and sedans. CNG, hybrid, LPG, and electric vehicles were tracked.     

西部地区公路快速客运系统关键技术研究

本篇依托＂西部地区公路快速客运系统关键技术研究＂项目,介绍了公路快速客运的概念、构成要素、服务对象、特征、发展现状及存在的主要问题,指出了公路快速客运系统的车辆、站场、服务、管理、信息等方面的关键技术,形成了公路快速客运系统评价模型,并提出了相应的快速客运发展对策及建议,为我国西部地区的公路快速客运系统建设与发展提供参考依据。     

基于LEAP模型的城市客运交通能耗和污染物排放预测

我国交通运输业能源消耗量与污染物排放量日益增多,交通部门的节能减排措施研究迫在眉睫。本论文基于LEAP模型构建了某城市客运交通能耗与污染物排放模型,并预测了基准情景、政策情景、技术情景及综合情景下该城市客运交通2014-2030年之间的能耗及污染物排放情况。研究表明,三种发展情景下该城市能源需求量及污染物排放较基准情景均有减少,其中综合情景效果最佳,综合情景在2030年的能源消耗与CO2排放可分别减少56.98%和54.55%,CO、HC、NOx与PM2.5可分别减排67.39%、67.27%、51.43%与75.38%。因此应大力发展公共交通,尤其是轨道交通,同时限制私家车的无节制发展,并推广节能环保技术以改善终端利用层次能源结构。     

公路绿化与环保的研究分析

为推动公路建设水平,确保公路正常运营和沿线生态环境可持续发展,文章总结了公路绿化的特点和功能,从安全性、经济性、生物多样性、景观性等方面分析了公路绿化设计的原则,并探讨了公路中央分隔带、路基边坡、互通立交、服务区的绿化设计内容,从公路环保的重要性,认知公路环保的内容、功能及意义,并多方角度的加以分析和采取措施,达到预期效果,把建设和环境紧密协调统一。并对公路环保的设计理念、评价指标、评价方法及施工阶段的环保措施进行了论述。     

Optimizing the process of designing and calculating railway catenary support infrastructure using a high-productivity computational tool

The process of designing and calculating railway catenary infrastructure, as the way it is carried out currently, is very complex and time consuming. It is necessary expert knowledge of different fields, like design and structural calculus, technical security, legal normative, topography, etc. This process consists of several stages aimed at choosing a design, checking requirements, and calculating structural feasibility, so the communication among the experts may be quite slow. In order to reduce time and effort invested in this process, we propose a system that allows to automate its stages and tasks. Our system provides a valid solution per structure, that complies with design and structural constraints, and with existing railway regulations. The proposed system has been integrated in a high-productivity software tool, that avoids human mistakes due to hand-calculation, allows users a fast design and calculation, and exploits the ability of current computers to run tasks concurrently so as to speed up the process. The computational performance and complexity of the tool, as well as statistics values, are analysed by designing and calculating up to 2048 heterogeneous support structures. Besides, the tool is evaluated through a study case based on a real railway route, obtaining an overall improvement of 82.33% in time invested over the existing process.     

A planning methodology for intelligent urban transportation systems

Recent developments in intelligent transportation systems pose new challenges and opportunities for urban transportation planning. To meet these challenges and to exploit these opportunities, a framework for a new transportation planning methodology has been developed. The methodology operates in a computer environment, called PLANiTS (Planning and Analysis Integration for Intelligent Transportation Systems), designed to facilitate the entire planning process form problem identification, through idea generation and analysis, on to prioritization and programming. To assist in problem identification, PLANiTS provides graphic representation of current conditions, including traffic, air pollution, accidents, and projections of future conditions. A computerized knowledge base, containing information about possible strategies and their effects, and a model base, containing transportation and other analysis models, are used to guide the user in identifying potentially effective strategies and performing the appropriate analysis. To facilitate the use of these tools, PLANiTS provides computer support of group processes such as brainstorming, deliberation, and consensus seeking. PLANiTS is designed for use in urban transportation planning at the local, regional, and state levels; it is intended to support a variety of participants in the planning process including transportation professionals, decision makers in transportation agencies (often local elected officials), citizens, and interest groups. Recognizing that transportation planning is essentially a deliberative, political process, PLANiTS is designed to inform and facilitate, but not replace, the political decision-making process.     

Urban passenger transport in the United States and Europe: a comparative analysis of public policies

This is the second part of a two‐part series that examines recent developments in urban passenger transport in the United States and Europe, focusing on the roles and impacts of the public sector as these have varied by country and over time. The first part of the series described public policies for roadway systems and private car use, whereas this second part concentrates on public transport. After a review of demand and supply trends, the article evaluates government policies in terms of public vs private ownership and operation, public regulation, financing responsibility by government level, types and amounts of subsidy, and impacts of ownership, regulation, and financing arrangements on costs and productivity. This second part concludes with an overall comparison between Europe and the United States, and considers how Europeans and Americans might learn from each other's successes and mistakes in order to improve transport policies.