Intent to purchase a plug-in electric vehicle: A survey of early impressions in large US cites

This paper examines consumer stated intent to purchase plug-in electric vehicles and assesses the factors that increase or decrease interest. We surveyed adult drivers in large US cities in early fall 2011, before vehicle manufacturers and dealers began marketing campaigns. The survey responses thus document early impressions of this transport technology. We find that, given current battery technology and public perceptions, overall stated intent to purchase or lease electric vehicles is low. Interest in plug-in hybrid technology is somewhat greater than interest in all-electric technology. Consumers who express early interest in adopting electric vehicles are typically highly educated, previous owners of conventional hybrids, environmentally sensitive, and concerned about dependence on foreign oil. Enhanced fuel economy, the primary tangible advantage of plug-in technology, is recognized as favorable by respondents but fails to exert a strong influence on purchasing intentions. Interest in plug-in electric vehicles is shaped primarily by consumers’ perceptions of electric vehicle disadvantages.     

Integration of vehicle routing and resource allocation in a dynamic logistics network

A shipper plans daily hub-to-hub transports within a hub and spoke network. Since a limited number of swap containers is available for transportation, two problems arise. 1. Swap containers have to be routed as pickup and delivery requests in multi-hub tours. 2. Day-by-day routing may lead to an imbalance of swap containers requiring a dynamic allocation. Neglecting interdependencies between vehicle routing and resource allocation seems inferior. An integration of the two problems overcomes this deficiency. We formulate mathematical models and propose integration approaches. The advantages of these approaches are discussed based on a computational study.     

Factors associated with proportions and miles of bicycling for transportation and recreation in six small US cities

The majority of bicycling in the US is for recreation rather than transportation purposes but few studies have examined the question of bicycling purpose. We use data from an online survey conducted in 2006 in six small cities in the western US to examine factors affecting bicycling for transportation compared to bicycling for recreation. The results indicate that individual, social-environment, and physical-environment factors have important influences on the balance between transportation and recreational bicycling and on miles of bicycling for each purpose. Bicycling comfort and an aversion to driving are associated with more transportation bicycling. A culture of utilitarian bicycling and short distances to destinations are also key factors for transportation bicycling. Bicycle infrastructure appears to play an indirect role through its effect on perceived bicycling safety and through the self-selection effect, by attracting bicycling-inclined people to bicycling-supportive communities.     

Planning and control of paratransit services in Hong Kong

As paratransit services, Hong Kong's taxis and public light buses (PLB) carried some 30% of the 9.7 million daily public transport boardings in Hong Kong in 1988. Most of the vehicles are individually owned, and services are operated as commercially viable concerns. While operators have a high degree of operational flexibility, taxis and PLBs are closely regulated by the Government. The fleet sizes are controlled by licensing. There is a system of zoning for taxis, and operational prohibitions and restrictions for PLBs. Over the years, Hong Kong has developed some practicable means of operational control on taxis and PLBs. It has been 20 years since PLBs were legalized in 1969. The transition experienced by this mode, from no control to regulated operations, signifies a major step forward from the point of view of transport administration. The Government's participation in the planning for PLB services has guided the development of this mode. In this paper, the planning and control mechanisms for Hong Kong's paratransit modes are introduced. Identified deficiencies are also discussed.     

The evolution,usage and trip patterns of taxis & ridesourcing services: evidence from 2001, 2009 & 2017 US National Household Travel Survey

Given the rapid adoption of ridesourcing services (RS), it is critical for transportation planners and policymakers to understand their impacts and keep policies up to date. This study contributes to the literature by using representative samples captured in the 2001, 2009 and 2017 National Household Travel Surveys to explore how taxis and ridesourcing (T/R) services have evolved and shaped people’s travel behavior pre- and post-disruption at the US national level. It characterizes and visualizes the asymmetries in demand spatially and temporally for T/R trips, showing that ridesourcing has greatly increased T/R trips from flexible and optional activity locations to home, which vary by times of day. It also characterizes tours involving T/R services, showing that while simple optional tours (such as home–recreation–home) represent the largest share of tours involving T/R, the fastest growth has been in simple mandatory tours (such as home–work–home). Tours involving T/R grew from 0.4% of all tours in 2009 to 1% of all tours in 2017, mostly within densely populated and transit-oriented regions. Although less than 1% of T/R trips involved a direct transfer to or from transit, one-third of all tours containing T/R also included transit. However, at the same time, 40% of T/R-containing tours also involved auto trip(s). Overall, this study reveals the complex relationships among their underlying sociodemographic characteristics, RS adoption and usage behavior, and daily tour patterns.

     

Organization and planning of ambulance transport services in England and Wales

The ambulance service is the largest special needs transport operator in England and Wales and an important pillar of support to the National Health Service. In the last decade its size and role as a transport agency have been the subject of at least two government‐inspired reviews which have questioned the efficiency of the ambulance service and examined in some detail its operational performance. The ambulance service also faces constraints on its funding, like the rest of the health service, which raises questions as to its ability in the future to meet all patient demands for transport, especially in the area of non‐emergency outpatient services. The organization of the ambulance service is described from a number of perspectives: historical, institutional and managerial. These suggest that changes occurring in the approach to health care and management which are based on assumptions of cost‐effectiveness and competition, will likewise affect the organization and provision of patient transport services. The ambulance service may become an even more specialist operator competing or co‐operating in certain areas of work with other transport agencies especially in the area of non‐emergency outpatient services. Scenarios are outlined on how this may be achieved and the likely implications for the delivery of health care.     

The impact of depot location,fleet composition and routing on emissions in city logistics

This paper investigates the combined impact of depot location, fleet composition and routing decisions on vehicle emissions in city logistics. We consider a city in which goods need to be delivered from a depot to customers located in nested zones characterized by different speed limits. The objective is to minimize the total depot, vehicle and routing cost, where the latter can be defined with respect to the cost of fuel consumption and CO₂ emissions. A new powerful adaptive large neighborhood search metaheuristic is developed and successfully applied to a large pool of new benchmark instances. Extensive analyses are performed to empirically assess the effect of various problem parameters, such as depot cost and location, customer distribution and heterogeneous vehicles on key performance indicators, including fuel consumption, emissions and operational costs. Several managerial insights are presented.     

试用TV成像技术研究长大隧道围岩地质参数

文章介绍了TV成像技术的定义和技术原理,阐述了应用该技术研究特长隧道围岩地质参数的特点和难点以及取得的研究成果,对今后该项技术的进一步推广和应用有促进作用.     

Changing relationships in the financing of elderly and handicapped transportation services

This paper reports the results of a national survey of providers of specialized transportation services who are recipients of UMTA Section 5 or Section 9 funding and report owning demand responsive vehicles (Section 15 report). The study reports a variety of service measures, financial data, cost containment activities and related information for fiscal years 1980 and 1982. For a limited number of systems, financial data for fiscal year 1984 are also reported. Analysis of the data indicates a general but as yet uncertain trend towards declining UMTA participation in funding these systems, increased fares and increased usage of cost containment and cost reduction techniques by the responding systems. Should the reported trends continue, then the responding systems could be expected to have financial difficulty in complying with the currently proposed regulations for the enforcement of Section 504 of the Rehabilitation Act of 1973.     

Integrating short turning and deadheading in the optimization of transit services

Urban transit demand exhibits peaks in time and space, which can be efficiently served by means of different fleets, increasing frequencies in those groups of stops with larger passenger inflow. In this paper we develop a model that combines short turning and deadheading in an integrated strategy for a single transit line, where the optimization variables are both of a continuous and discrete nature: frequencies within and outside the high demand zone, vehicle capacities, and those stations where the strategy begins and ends. We show that closed solutions can be obtained for frequencies in some cases, which resembles the classical “square root rule”. Unlike the existing literature that compares different strategies with a given normal operation (no strategy - single frequency), we use an optimized base case, in order to assess the potential benefits of the integrated strategy on a fair basis. We found that the integrated strategy can be justified in many cases with mixed load patterns, where unbalances within and between directions are observed. In general, the short turning strategy may yield large benefits in terms of total cost reductions, while low benefits are associated with deadheading, due to the extra cost of running empty vehicles in some sections.     

埋地钢制管道基于SCM检测仪的杂散电流测试与评价

杂散电流能够对埋地钢制管道造成很大的危害和破坏,严重影响管道的安全运行.应用智能杂散电流检测仪( SCM)对埋地钢制管道上的杂散电流干扰进行测试,通过对检测结果分析发现,智能杂散电流检测仪功能齐全,能够沿管道路线检测管道上各种杂散干扰电流的大小和方向,排除不需要的干扰信号,确定干扰源类型和来源;能够准确判断管道上杂散电...     

高含水集输管道内腐蚀预测与检测技术及应用

高含水油气管道内腐蚀穿孔频发,严重影响生产和环境.因此,油气管道内腐蚀的预测与检测是亟待解决的问题.常规检测耗资大,且效果差,结合美国腐蚀工程师协会内腐蚀直接评价标准和流体数值仿真技术(CFD)预测管道内腐蚀模型并与现场管道高程数据相结合,实现对高含水油气管线积水与易发内腐蚀位置的预测,针对该位置开展管体腐蚀检测,该方法在现场得到成功应用.通过现场检测数据来验证和修正预测模型,为解决高含水油气管道内腐蚀提供一种方法.     

Economic and emissions impacts of renewable fuel goals for aviation in the US

The US Federal Aviation Administration (FAA) has a goal that one billion gallons of renewable jet fuel is consumed by the US aviation industry each year from 2018. We examine the economic and emissions impacts of this goal using renewable fuel produced from a Hydroprocessed Esters and Fatty Acids (HEFA) process from renewable oils. Our approach employs an economy-wide model of economic activity and energy systems and a detailed partial equilibrium model of the aviation industry. If soybean oil is used as a feedstock, we find that meeting the aviation biofuel goal in 2020 will require an implicit subsidy from airlines to biofuel producers of $2.69 per gallon of renewable jet fuel. If the aviation goal can be met by fuel from oilseed rotation crops grown on otherwise fallow land, the implicit subsidy is $0.35 per gallon of renewable jet fuel. As commercial aviation biofuel consumption represents less than 2% of total fuel used by this industry, the goal has a small impact on the average price of jet fuel and carbon dioxide emissions. We also find that, under the pathways we examine, the cost per tonne of CO₂ abated due to aviation biofuels is between $50 and $400.     

Dual influences on vehicle speed in special-use lanes and critique of US regulation

We verify that slow speeds in a special-use lane, such as a carpool or bus lane, can be due to both, high demand for that lane and slow speeds in the adjacent regular-use lane. These dual influences are confirmed from months of data collected from all freeway carpool facilities in the San Francisco Bay Area. Additional data indicate that both influences hold: for other types of special-use lanes, including bus lanes; and for other parts of the world.The findings do not bode well for a new US regulation stipulating that most classes of Low-Emitting Vehicles, or LEVs, are to vacate slow-moving carpool lanes. These LEVs invariably constitute small percentages of traffic; e.g. they are only about 1% of the freeway traffic demand in the San Francisco Bay Area. Yet, we show: that relegating some or all of these vehicles to regular-use lanes can significantly add to regular-lane congestion; and that this, in turn, can also be damaging to vehicles that continue to use the carpool lanes. Counterproductive outcomes of this kind are predicted first by applying kinematic wave analysis to a real Bay Area freeway. Its measured data indicate that the site selected for this analysis stands to suffer less from the regulation than will others in the region. Yet, we predict: that the regulation will cause the site’s people-hours and vehicle-hours traveled during the rush to each increase by more than 10%; and that carpool-lane traffic will share in the damages. Real data from the site support these predictions. Further parametric analysis of a hypothetical, but more generic freeway system indicates that these kinds of negative outcomes will be widespread. Constructive ways to amend the new regulation are discussed, as are promising strategies to increase the vehicle speeds in carpool lanes by improving the travel conditions in regular lanes.     

Fare deregulation of transit services: Winners and losers in a competitive market

Currently, the Hong Kong government imposes fare control on buses and taxi while the rail services are immune to such a control. This study examined four scenarios of fare deregulation on transit services by considering three related parties of a transit system – service providers, travelers, and society in general, with their respective objectives represented as – revenue, travel utility, and congestion. Analyzing the resultant impacts on these three parties, we found that a different regulatory environment would favor or hurt a different set of parties. There is no clear win‐win situation for all parties. Deciding a socially acceptable regulatory environment is likely to involve difficult tradeoffs among these parties.     

Factors affecting the use of bus and rail services in a deregulated environment

In 1987, the NSW Government commenced deregulation of the long-distance bus industry in NSW. This immediately led to greater inter-modal competition and contestability within the context of changing passenger markets.This study utilises categorical data analysis methods to examine the emerging passenger markets of inter-modal competitors (bus and rail) and to assess the relative importance of socioeconomic and travel related variables which affect the use of bus and rail services along the high volume Sydney-Canberra and Sydney-North Coast corridors.Conclusions from the study indicate varied passenger markets within a relatively new contestable environment which are mode and corridor specific. Results are indicative of the need for competitors to develop marketing strategies conducive to the demands of the travelling public in order to enhance viability and commercial opportunities.     

特大断面隧道液压模板台车的研制与施工技术

文章以重庆轻轨较新线临江门车站隧道为例,介绍了特大断面隧道整体式液压模板台车的研制与全断面衬砌施工技术,可供同类工程参考。     

关于挤压性围岩隧道大变形的探讨和研究

当前挤压性围岩大变形问题已引起隧道工程界的高度重视,但系统研究并不多,至今亦未列入设计规范.文章根据大变形的机理,提出了大变形的定义以及现场判定和预测方法,并按照主动法的整治原则提出了针对不同程度大变形隧道的设计与施工建议,可供设计施工以及今后修编规范时参考.     

大跨变断面隧道穿行式混凝土液压小模板衬砌台车设计方案

三线大跨变断面隧道,不仅断面变化频繁,而且其中线向左、右偏移很不规则,这就要求衬砌台车既要解决隧道断面的变化问题,又要保证大跨整体的衬砌质量.文章所介绍的衬砌台车设计方案巧妙地利用了分解式的台车拱部结构,将大跨变断面结构、衬砌外观质量、经济技术论证与工期安排等因素处理到了最佳状态.     

The use of patent analysis in assessing ITS innovations: US,Europe and Japan

A wealth of research on ITS has been carried out for the past two decades. In view of the rapid technological development and innovations occurring in ITS, the ITS stakeholders need to be aware of the usefulness and availability of patents associated with ITS technology. Among the national and international reviews which have been made available in journals of record and freely available public sources, little use has been made of patent information in assessing ITS innovations. Therefore, the paper looks at the ITS technology developments from the international perspective through utilizing rich, reliable information provided by ITS-related invention patents in the world’s three leading patent databases (EPO, USPTO, and JPO) to provide an overall picture of ITS innovations. The research findings show that the patent analysis can provide firms involved in the ITS sector and ITS researchers with information that can assist in their strategic planning efforts.