低碳背景下城市交通需求管理策略

为了探索低碳背景下,交通需求管理策略的具体设置应用,本文按照需求管理四个层面,探讨碳排放对于需求管理措施的影响,并在此基础上,以出行分布熵模型为基础,建立基于低碳背景下的需求管理多目标双层规划模型;随后,通过一个P&R系统(Park and Ride)案例,采用遗传算法,利用MATLAB、TRANSCAD等软件,进行模型的求解以及具体的路网流量分配,分析所建立模型在交通需求管理措施实行时的可靠与准确程度。     

基于低碳交通下的产品再设计研究

低碳产品虽然在国内兴起不久,却备受各界人士的追捧,原因在于人们从过度的"以人为本"设计中幡然醒悟,开始追求低排放,低耗能的设计与生活环境。本文将立足于低碳交通下的产品再设计研究,综合对比国内外低碳产品设计现状,指出设计中和运用中的不合理处,通过再设计方法的重建,来研究解决现存问题,并得出相应研究结论。低碳交通产品再设计是解决环境污染的重要方法和途径。     

低碳环境下车辆路径问题研究

车辆路径问题(VRP)是供应链管理中的关键问题,同时环境问题又是物流领域亟待解决的主要问题之一,所以在研究VRP过程中结合当前环境是研究低碳运输的重要方式。为实现低碳运输,文中计算油耗时考虑了车辆的载重和车速,并以最少成本作为目标函数对VRP进行研究,建立数学模型,对传统的人工蜂群算法进行改进,最后通过matlab软件进行仿真实验。     

城市交通低碳化发展策略研究

随着我国城市机动车保有量快速增长,污染物排放总量持续攀升,所带来的城市污染问题日趋严重,发展低碳交通成为我国城市交通发展的战略方向。本文基于我国城市交通低碳化发展现状及存在问题及影响因素,结合国外发达国家城市交通低碳化的发展经验,分析了城市交通低碳化发展的外因和内因及存在的主要问题,提出在我国能源结构短期内难以发生根本性改变的情况下,大力和优先发展公共交通,逐步建立以大运量轨道交通和快速交通为骨干、常规公共汽电车为主体、其他公共交通方式为补充的城市公共交通体系,将是实现城市交通低碳化和可持续发展最有效的途径。同时,还需不断提高交通能效,开发和利用可再生能源,提高交通运输管理水平,引导公众理性选择出行方式。     

基于低碳理念的城市慢行交通发展模式研究

慢行交通系统发展模式是城市交通发展模式研究的重要内容,也是低碳交通、可持续发展交通的重点研究领域。文章介绍了慢行交通的特点、定位及研究现状,并结合我国当前城市发展实际,提出了一系列基于低碳理念的城市慢行交通发展新模式。     

探讨绿色低碳理念在公路设计中的体现

绿色环保理念已在公路建设行业中拥有很大的号召力,其已贯穿了整个公路建设项目的规划、施工等各个阶段。本文结合作者工作经验,探讨了公路设计中绿色低碳理念的应用,主要从概念、应用、路基面设计、节能环保几个方面进行了分析,提出在交通运输行业中引入绿色低碳的理念,为我国走可持续发展战略做出应有贡献,有效地响应了我国实施节能减排、低碳环保的号召。     

316Lmod尿素级超低碳不锈钢焊接技术

介绍了在高温、高压、高腐蚀性介质中工作的尿素装置采用的316Lmod尿素级超低碳不锈钢材料及其焊接技术要求。焊接接头具有优良的抗焊接热裂纹性能和抗晶间腐蚀性能是焊接技术的关键。在焊接工艺评定基础上,制定了合理的产品现场焊接工艺,包括焊接材料的选择、坡口形式及尺寸设计、焊接规范参数以及焊接过程中出现的问题及解决方法。实践证明:对产品焊接的全过程进行严格控制,能够获得优良的焊接质量。     

广东省绿色低碳航道建设途径研究

本文在深入调研分析广东省航道的建设情况和节能减排工作的基础上,分析广东省航道局在绿色航道方面取得的成绩和存在的问题,结合广东省航道绿色低碳发展的总体要求和工程特点,制定了航道绿色发展的总体思路和发展目标,确定了切实可行的主要任务,并进行了相关节能减排主要技术的适用性分析,并提出了相应的保障措施,目的是研究绿色低碳航道建设途径,科学、系统地指导广东省绿色低碳航道建设工作,也可为全国其他地区绿色低碳航道建设提供参考。     

低碳经济下城际与城市周边公路交通模式研究

随着人们收入的不断提高及汽车业的快速发展,汽车大量进入普通家庭,但由此产生的碳排放带来的城市环境问题也日益严峻,如何落实低碳交通理念,消减碳排放,已成业界研究的焦点;另外,近年来交通堵塞亦愈发严重,如何解决此问题也一直是困扰人类的难题。本文就如何在低碳经济下发展公路交通进行研究,从城市交通规划设计思想上提出一套全新模式。首先在交通始端将车提至某高度,利用重力和动力使车加速;其次是关键路段,在该段利用倾斜角度使车实现匀速行驶;最后是到达目的地前几公里段,让车行驶在平整公路上以便车流分解。在此思想模式引导下,做出新型公路设计,并对其进行分析。这种创新将丰富低碳交通的理论和方法体系,为建设低碳运输提供重要的思路,对改善现行交通中存在的重大问题,具有一定的现实意义。     

低碳生态视角下哈尔滨市绿色交通及可持续发展对策研究

随着城市化和机动化的快速发展,出现了交通拥堵、交通安全及交通污染等一系列问题。为了缓解这些问题及推动哈尔滨市低碳生态城市建设,发展绿色交通已经迫在眉睫。本文在分析了哈尔滨市交通发展状况基础上,主要从构建一体化公共交通系统、自行车及步行慢行系统等五个方面探讨了哈尔滨市绿色交通及可持续发展对策。     

Mobility evaluation for urban public transportation

Summary

This paper has reported on a study of relative opportunity—not absolute opportunity. Minimum absolute standards for mobility or accessibility are difficult to justify. Some additional study into the development and application of absolute mobility standards may be warranted.

The application of the mobility evaluation model has primarily focused upon a corridor line‐haul system. Conclusions suggest that such a system will not markedly improve existing transit mobility levels in either the peak hour or the off‐peak. The experimental work has verified this conclusion, and more importantly, it has detailed quantitatively the exact levels and spatial distribution of mobility improvements. However, this study does not include a comprehensive analysis of all methods of mobility enhancement, nor does it undertake a comparison of alternative means of mobility improvement. Certainly other methods to improve access to opportunities should be explored before policy considerations are finalized. These methods include other transit solutions, land use alternatives, socio‐economic policies, and other‐mode transportation alternatives. The accessibility technique and mobility indices approach appears to have general applicability in the analysis of optimal strategies for system evaluation.

Of interest is an examination of alternative feeder transit systems to the corridor line. Additional research with the model might point out the maximum mobility effects expected through improved collector service in the suburbs, with corridor line‐haul to the CBD.

The indices are also readily available for a comparison of mobility patterns for different urban areas. Application of the program to transit and socio‐economic data for a set of cities would yield an indication of the relative mobility levels provided. Such data might be considered as an evaluation criterion for future transit funding by federal officials.

In addition, the model is currently being considered by UMTA as a tool to aid in the evaluation of the equitable distribution of transit system benefits as defined in Title VI of the Civil Rights Act of 1964.²⁵ The mobility output would serve as an indicator of the levels‐of‐service provided to certain disadvantaged urban groups. For this application the computer model is being altered to achieve compatability with the Transportation Planning System (UTPS) computer model package developed by UMTA.     

Towards integrated traveller information

Traveller information provision has become a key government priority in the UK following the publication of its Transport White Paper in July 1998. Developments are already underway for the integration of information systems across different public transport modes and between public transport information systems covering different regions. The Highways Agency (which is responsible for managing the strategic road network in the UK) is also advancing in its development of information databases and systems for the motorist. This paper considers the prospect of providing travellers with multimodal information with integration of driver information with public transport information. If such integration can be achieved then travellers, and in particular drivers, have the prospect of being presented with comparable information on travel options across modes. An integrated information service has a great potential to inform and influence travel choices. The paper considers the issue of travel choices and the role that information can play particularly in the context of mode choice. The political (UK) and technological climate for information provision is outlined. The paper identifies issues that will need to be addressed to identify the requirements from, and potential benefits of, integrated information, and the obstacles and challenges likely to be faced in moving towards it. Driver reactions, in particular, to the prospect of integrated information provision are fundamental to the assessment of its potential importance and value.     

Towards data-driven car-following models

Car following models have been studied with many diverse approaches for decades. Nowadays, technological advances have significantly improved our traffic data collection capabilities. Conventional car following models rely on mathematical formulas and are derived from traffic flow theory; a property that often makes them more restrictive. On the other hand, data-driven approaches are more flexible and allow the incorporation of additional information to the model; however, they may not provide as much insight into traffic flow theory as the traditional models. In this research, an innovative methodological framework based on a data-driven approach is proposed for the estimation of car-following models, suitable for incorporation into microscopic traffic simulation models. An existing technique, i.e. locally weighted regression (loess), is defined through an optimization problem and is employed in a novel way. The proposed methodology is demonstrated using data collected from a sequence of instrumented vehicles in Naples, Italy. Gipps’ model, one of the most extensively used car-following models, is calibrated against the same data and used as a reference benchmark. Optimization issues are raised in both cases. The obtained results suggest that data-driven car-following models could be a promising research direction.     

Older People's Mobility: Segments,Factors, Trends

Abstract

The expanding older population is increasingly diverse with regard to, for example, age, income, location, and health. Within transport research, this diversity has recently been addressed in studies that segment the older population into homogeneous groups based on combinations of various demographic, health-related, or transport-related factors. This paper reviews these studies and compares the segments of older people that different studies have identified. First, as a result of a systematic comparison, we identified four generic segments: (1) an active car-oriented segment; (2) a car-dependent segment, restricted in mobility; (3) a mobile multi-modal segment; (4) and a segment depending on public transport and other services. Second, we examined the single factors used in the reviewed segmentation studies, with focus on whether there is evidence in the literature for the factors’ effect on older people's travel behaviour. Based on this, we proposed a theoretical model on how the different determinants work together to form the four mobility patterns related to the identified segments. Finally, based on current trends and expectations, we assessed which segments are likely to increase or decrease in future generations of older people and what should be done to support the multi-optional and independent mobility of older people.     

我国机动化发展态势及影响因子分析

我国当前处于城镇化、机动化的高速发展阶段,机动车数量呈现井喷式增长,有必要对其增长规律进行研究并预测其未来发展趋势。本文重点研究我国机动车增长特点、饱和状态及重要因素影响作用。本文以已有机动化"五阶段"发展规律为基础,通过全国范围内实施3000余份问卷调查,分析研究了公共交通服务水平对机动车购买及使用的影响;通过对不同机动化限制政策的分析、对比、总结,探索政策限制对机动化进程的影响。并以这两个因素的变化设立不同情景,探索不同情景下我国机动车增长及饱和值变化。     

Towards a real-time microscopic emissions model

This article presents a new approach to microscopic road traffic exhaust emission modelling. The model described uses data from the SCOOT demand-responsive traffic control system implemented in over 170 cities across the world. Estimates of vehicle speed and classification are made using data from inductive detector loops located on every SCOOT link. This data feeds into a microscopic traffic model to enable enhanced modelling of the driving modes of vehicles (acceleration, deceleration, idling and cruising). Estimates of carbon monoxide emissions are made by applying emission factors from an extensive literature review. A critical appraisal of the development and validation of the model is given before the model is applied to a study of the impact of high emitting vehicles. The article concludes with a discussion of the requirements for the future development and benefits of the application of such a model.     

Towards universal freeway incident detection algorithms

This paper reports the intensive test of the new transport systems centre (TSC) algorithm applied to incident detection on freeways. The TSC algorithm is designed to fulfil the universality expectations of automated incident detection. The algorithm consists of two modules: data processing module and incident detection module. The data processing module is designed to handle specific features of different sites. The Bayesian network based incident detection module is used to store and manage general expert traffic knowledge, and to perform coherent reasoning to detect incidents. The TSC algorithm is tested using 100 field incident data sets obtained from Tullamarine Freeway and South Eastern Freeway in Melbourne, Australia. The performance of the algorithm demonstrates its competitiveness with the best performing neural network algorithm which was developed and tested using the same incident data sets in an early research. Most importantly, both the detection rate and false alarm rate of the TSC algorithm are not sensitive to the incident decision threshold, which greatly improves the stability of incident detection. In addition, a very consistent algorithm performance is achieved when the TSC algorithm is transferred from Southern Expressway of Adelaide to both Tullamarine Freeway and South Eastern Freeway of Melbourne. No substantial algorithm retraining is required. A significant step towards algorithm universality is possible from this research.     

Moving from trip-based to activity-based measures of accessibility

This paper studies the properties and performance of a new measure of accessibility, called the activity-based accessibility (ABA) measure, and compares it to traditional measures of accessibility, including isochrone, gravity and utility-based measures. The novel aspect of the ABA is that it measures accessibility to all activities in which an individual engages, incorporating constraints such as scheduling, and travel characteristics such as trip chaining. The ABA is generated from the day activity schedule (DAS) model system, an integrated system based on the concept of an activity pattern, which identifies the sequence and tour structure among all the activities and trips taken by an individual during a day. A byproduct is an individual’s expected maximum utility over the choices of all available activity patterns, and from this the ABA is derived. The ABA is related to the logsum accessibility measures frequently derived from destination and mode discrete choice models. The key difference is that it is generated not by examining a particular trip, but by examining all trips and activities throughout the day.A case study using data from Portland, Oregon, demonstrates the rich picture of accessibility made available by use of the ABA, and highlights differences between the ABA and more traditional measures of accessibility. The ABA is successful in (a) capturing taste heterogeneity across individuals (not possible with aggregate accessibility measures), (b) combining different types of trips into a unified measure of accessibility (not possible with trip-based measures), (c) reflecting the impact of scheduling and trip chaining on accessibility (not possible with trip-based measures), and (d) quantifying differing accessibility impacts on important segments of the population such as unemployed and zero auto households (not possible with aggregate measures, and limited with trip-based measures).