Ridesharing in North America: Past,Present, and Future

Since the late 1990s, numerous ridematching programmes have integrated the Internet, mobile phones, and social networking into their services. Online ridematching systems are employing a range of new strategies to create “critical mass”: (1) regional and large employer partnerships, (2) financial incentives, (3) social networking to younger populations, and (4) real-time ridematching services that employ “smartphones” and automated ridematching software. Enhanced casual carpooling approaches, which focus on “meeting places”, are also being explored. Today, ridesharing represents approximately 8–11% of the transportation modal share in Canada and the USA, respectively. There are approximately 638 ridematching programmes in North America. Ridesharing's evolution can be categorized into five phases: (1) World War II car-sharing (or carpooling) clubs; (2) major responses to the 1970s energy crises; (3) early organized ridesharing schemes; (4) reliable ridesharing systems; and (5) technology-enabled ridematching. While ridesharing's future growth and direction are uncertain, the next decade is likely to include greater interoperability among services, technology integration, and stronger policy support. In light of growing concerns about climate change, congestion, and oil dependency, more research is needed to better understand ridesharing's impacts on infrastructure, congestion, and energy/emissions.     

地下结构抗震设计方法的比较与分析

在日本阪神大地震中,地下结构遭到了严重破坏,因此地下结构的地震反应及抗震设计和安全性评价越来越被重视。首先采用矩形地下结构的两种抗震设计方法——拟静力法和反应位移法对北京地铁北宫门车站进行了抗震计算,并使用计算软件FLAC4.0对北宫门车站进行了时程分析,发现拟静力法对地震荷载过于简化,致使其过低估计了地震对地下结构的影响;而反应位移法较合理地反应了地震荷载对地下结构的影响;地震中的惯性力对地下结构的内力影响不大,地震剪应力对结构的内力影响最大;并且,通过软件FLAC时程分析,得到的位移等反应规律与反应位移法的假设相同,计算得到的弯矩值与采用反应位移法计算得到的弯矩值相近。因此,推荐首先采用反应位移法进行地下结构的抗震设计。     

Transportation modeling: Lessons from the past and tasks for the future

In spite of the recent progress made in household activity analysis and travel budget studies, urban transportation modeling still remains a “not-too-well developed” research field. There are conflicting theories, analysis units are not uniform, terms are not precisely defined, basic studies of sub-systems involved are not yet completed, and many models lack behavioral background as well as basic attributes such as simplicity, sensitivity, compatibility, transferability and forecasting ability. Gaps in methodology may be partially responsible for this situation. There is an urgent need for simple, yet not primitive, easily applicable urban transportation models which can respond to the technical needs of planners and engineers. Lessons from the past, as well as experiences from other disciplines, suggest that future research should concentrate on: (1) new, “unconventional” approaches based on systematic, basic studies of all sub-systems involved; (2) proper definition and stratification of an analysis unit; (3) revision and unification of definitions, classifications, etc., in order to improve the behavioral background of the models; (4) dynamic rather than static approaches, able to describe feedbacks between transportation and land-use as well as between transportation demand and supply; (5) interrelations between subsequent sub-models, particularly between car availability, trip generation and modal split; (6) developing models which are not only sensitive to transportation policies but also to other local policies (e.g. land use, city development, social, etc.).     

Sustainable Transport in the European Union: A Review of the Past Research and Future Ideas

Abstract

This paper presents a review of the research on the sustainability of transport systems carried out over the last 15 years for the European Union (EU), identifies some missing gaps and elaborates on the prospective future ideas. The general concept of sustainable development and definitions of sustainability of transport systems and their operationalization are discussed. These are followed by the general review of the research on the sustainable transport systems funded by the EU 4th, 5th and 6th Framework Programs. Consequently, refinement of existing and/or developing an innovative system for monitoring sustainability of transport systems in the EU based on the indicator system(s) of performances is suggested as a prospective research idea.     

Contractual PPPs for Transport Infrastructure in Spain: Lessons from the Economic Recession

In this paper, we analyse the successes and failures of contractual public-private partnerships (PPPs) for delivering and operating transport infrastructure in Spain from the award of the first toll highway concession programme to the present. To that end, we show the risk allocation principles used in Spain and explore the evolution of the contracting approaches over the years. We found that the performance was reasonably good until the arrival of the economic crisis in 2008. Taking advantage of that, we make a review of contractual PPPs for different transport modes and assess the impact that the economic crisis has had on their business performance and the capacity of the central and regional governments to fulfil their commitments with the private sector. This analysis enabled us to identify measures that, if had been applied, would have improved the resilience of these contract during the economic crisis.     

Making Cycling Irresistible: Lessons from The Netherlands,Denmark and Germany

Abstract

This article shows how the Netherlands, Denmark and Germany have made bicycling a safe, convenient and practical way to get around their cities. The analysis relies on national aggregate data as well as case studies of large and small cities in each country. The key to achieving high levels of cycling appears to be the provision of separate cycling facilities along heavily travelled roads and at intersections, combined with traffic calming of most residential neighbourhoods. Extensive cycling rights of way in the Netherlands, Denmark and Germany are complemented by ample bike parking, full integration with public transport, comprehensive traffic education and training of both cyclists and motorists, and a wide range of promotional events intended to generate enthusiasm and wide public support for cycling. In addition to their many pro‐bike policies and programmes, the Netherlands, Denmark and Germany make driving expensive as well as inconvenient in central cities through a host of taxes and restrictions on car ownership, use and parking. Moreover, strict land‐use policies foster compact, mixed‐use developments that generate shorter and thus more bikeable trips. It is the coordinated implementation of this multi‐faceted, mutually reinforcing set of policies that best explains the success of these three countries in promoting cycling. For comparison, the article portrays the marginal status of cycling in the UK and the USA, where only about 1% of trips are by bike.     

Transit subsidies and regulation: Lessons from the Israeli experience

The Israeli transport sector, like those of many other countries is subject to complete government control with regard to fares, entry into the market, terms of operation and subsidies. It is unique, however, in that the fares charged are remarkably low and that the major transit mode, buses, is operated by privately owned companies. This paper explores what makes this low level of fares possible and in doing so examines the principal characteristics of the sector. It shows that this phenomenon cannot be explained by the amount of subsidy given to the operators but must be attributed to other factors, mainly the efficiency in the production of the services which is motivated by the profit maximization objective of the operators. The paper further argues that government policies regarding subsidy and regulation are generally inefficient as they cause misallocation of resources.     

Telecommuting and environmental policy: Lessons from the ecommute program

In 1999 the National Air Quality and Telecommuting Act established pilot telecommuting programs (ecommute) in five major US metropolitan areas. The major goal of the ecommute program was to examine whether a particular type of economic incentive, tradable emissions credits from telecommuting, represents a viable strategy for reducing vehicle miles traveled and improving air quality. A context is established for evaluating whether the envisioned trading scheme represents a feasible approach to reducing mobile source emissions and promoting telecommuting and a review of the limited experience with mobile source emissions trading programs is provided. Using two-and-one-half years of data collected in the ecommute program, telecommuting frequency, mode choice, and emissions reductions are examined. It is found that from a regulatory perspective, the most substantial drawback to such a program is its questionable environmental integrity, resulting from difficulties in designing sufficiently rigorous quantification protocols to accurately measure the emissions reductions from telecommuting. Such a program is not likely to be cost-effective because the emissions reductions from a single telecommuter are very small.     

The future of transit technology: Lessons from EXPO 86

Expo 86, the World Exposition held last year in Vancouver, Canada, was the largest, special-category world's fair ever staged, with 54 international participants. Given the designated theme of transportation and communications, it is interesting to interpret the statements made by the participants in regard to particular sub-theme areas such as urban transit. This paper reviews the presentations (exhibits, demonstrations, conferences, and seminars) developed by all participants in Expo 86 in regard to urban transit technology, and assesses the significance and direction of technological developments in the areas of vehicle and terminal design, network and system operation and control, and planning and management systems.     

Understanding travel behaviour change during mega-events: Lessons from the London 2012 Games

This paper presents results from a longitudinal study of the travel behaviour change associated with the London 2012 Olympic and Paralympic Games (the ‘Games’). The research examines commuter travel behaviour through a panel approach enabling an understanding of individual behaviour across three waves (before, during and after), with the study utilising unique access to a Transport for London panel study (n = 1132). The findings indicate that a substantial amount of change occurred during the Games (54% made at least one change), with reducing or re-timing journeys being the most likely adaptations made. A key objective of this work was to advance the discussion about the theoretical constructs that are most applicable in the study of behaviour change associated with disruptive events, which was done through the application and critical evaluation of the Transtheoretical Model. The insights from the stages of change element of the model were relatively limited but the analysis shows significant differences in the underlying factors explaining change according to the type of change made (reduce, re-time, re-mode and re-route). Whilst the long-term behavioural impacts of events like the Games appear small, the study has uncovered a need to consider these behavioural choices as distinct rather than under the collective term of “travel behaviour change”, as is current practice.     

Implementing Road User Charging: The Lessons Learnt from Hong Kong,Cambridge and Central London

Abstract

This paper studies the possibility of increasing shipping of fruit and vegetables from Almería (southeast of Spain) to Port Vendres‐Perpignan (southeast of France). Almería is one of the areas of vegetables production largest in the world and Perpignan is one of the most important customers of Almería. After analysing the potential volume of shipping, we estimate a mode choice model which allows us to study the sensitivity of final clients (horticultural operators) to future change in the variables which condition the choice between transport by sea or by land. This will also help us to calculate the market share of each system as a function of foreseeable change in the variables.     

The desulphurisation of shipping: Past,present and the future under a global cap

As from January 2020, the International Maritime Organization (IMO) is implementing a global 0.5% limit on the sulphur content of fuel, commonly known as the global sulphur cap. This limit is the latest policy in the efforts to reduce sulphur emissions from shipping, following the designation of emission control areas (ECAs) and other regional regulations. In this paper, a literature review is conducted of academic studies that have dealt with issues relating to the reduction of maritime sulphur emissions. Various recurring research themes are identified, spanning the areas of operations research, maritime economics and transport policy. The effects and implications of available compliance options are then analyzed from the perspectives of ship operators, shippers and consumers. Using lessons learned from the enforcement of ECA regulations, this is followed by an appraisal of various potential issues related to the enforcement of these new global regulations. It is found that a homogeneous enforcement regime is required to ensure a level playing field amongst ship operators and that the global sulphur cap may lead to serious market distortion, due to the potential short term rise of fuel prices. The paper concludes with a set of recommendations for future research on sulphur emissions from shipping in the aftermath of the global cap and, looking forward, to its relationship to the IMO strategy on the reduction of greenhouse gas (GHG) shipping emissions.     

Transport Innovation: Coping with the Future

An efficient transport system is a crucial precondition for economic development and an asset in international mobility. Mobility of passengers and transport of goods are considered key elements for a modern society. The transport sector is also a sector of continuous technological innovation. However, there is considerable uncertainty surrounding future transport technology and policy, as well as a large variation in ways to deal with this uncertainty. With regard to the latter it may be helpful to use more than one foresight method, e.g. a combination of methods each with a different emphasis on expertise, creativity and interaction with actors. Such a multiple method approach allows for the identification of those futures or future developments that are robust. This paper provides an introduction to the topic of transport innovation as well as providing a context for the four papers which follow in this special issue, illustrating the importance of taking such a multiple method approach.     

钻爆法海底隧道软弱破碎地层注浆加固堵水技术浅析

为了解决海底隧道穿越软弱破碎地层所遇到的技术难题,文章针对海底隧道软弱破碎地层特点,从超前地质预报、注浆方案选择标准、注浆材料、注浆参数、注浆工艺以及注浆效果检验方面进行了分析总结,提出了钻爆法海底隧道软弱破碎地层注浆加固堵水技术和总体对策,并阐述了其在工程中的应用效果.     

Public/private-sector cooperation in urban transportation: Lessons from ridesharing experiences in Connecticut

An important characteristic of urban transportation policy and planning today is the increasing role that the private sector is playing in identifying and implementing transportation projects. For example, a recent examination of the possible forms of such involvement found that there were four major categories of action that could be used to classify recent private-sector efforts in urban transportation: (1) aid to and/or provision of transportation services; (2) formation of advocacy or advisory groups whose purpose is to influence public policy; (3) sponsorship of transportation studies; and (4) provision of management assistance to public agencies (Gordon, 1982). In many of these efforts, the successful implementation of a project or program required close cooperation between public and private-sector officials. The purpose of this paper is to examine the characteristics of this interaction and explore the implications for transportation planning and policy.Examples of public/private-sector interaction in two Connecticut cities, Hartford and Stamford, are used to illustrate the characteristics of successful transportation program implementation. Although the examples are limited to two cities, and are mainly concerned with one major category of action (ridesharing), the characteristics of the process used and of the results can be applied to other situations where public/privatesector interaction is desired.     

Twenty Years of Rail Crowding Valuation Studies: Evidence and Lessons from British Experience

Abstract

This paper reviews evidence from British experience of the valuation of rail crowding obtained over 20 years from 17 studies. It summarizes these studies, places some useful empirical evidence in the public domain and draws lessons from this considerable body of evidence and experience. Crowding valuations, both for standing and seated in crowding conditions, are summarized in terms of time multipliers, which are inherently more transferable than monetary equivalents. A meta‐analysis of 208 valuations is reported, finding the valuations to vary with load factor and journey purpose. The seating multiplier averages 1.19 and the standing multiplier averages 2.32. The latter is in line with widely used multipliers applied to walking and waiting time. The most recent evidence is based around the number of standing passengers per square metre, thereby providing a more accurate measure of the discomfort of standing since, unlike load factor, it allows for the layout of the carriage and ease with which crowding can be accommodated. As far as methodology is concerned, the paper covers issues such as presenting crowding in ‘stated preference’ exercises and the realism of the crowding levels offered, non‐linearities in the relationship between crowding multipliers and the severity and amount of crowding time, and probabilistic versus deterministic representations of crowding. The paper also identifies future areas for research.     

广州地铁二号线越-三区间隧道盾构工程衬砌管片接缝防水技术

文章着重介绍了广州地铁二号线越-三区间隧道盾构工程管片接缝防水的设计和施工技术,以期为今后类似工程提供借鉴.     

志同道合力促工程技术进步联手服务谋取建设事业发展——纪念中国土木工程学会隧道及地下工程分会成立三十周年

公元1979年的2月27日,在地处四川峨眉的西南交通大学校园内,以刘圣化校长为首的多名国内隧道及地下工程专家、学者按照中国土木工程学会的统一部署发起成立了隧道工程学会并组成了第一届理事会.紧接着于2月28日～3月5日召开了主题为"中国隧道工程发展"的首次学术研讨会,200多人济济一堂,宣读、交流科技论文上百篇,气氛热烈,盛况空前,从此开始了我国隧道及地下工程学界携手同进、共谋发展的崭新局面.同年,隧道工程学会代表国家加入国际隧道协会(ITA),为成员国之一.1982年,原隧道工程学会改名为隧道与地下工程学会,1987年,应学会管理工作的需要,又改名为隧道及地下工程分会.     

深覆土输水隧洞与进洞井接头防水设计与施工技术

隧洞及井接头防水作为一项关键工序,对输送饮用水的青草沙过江管隧洞工程尤为重要。文章以此为工程背景,结合深覆土输水隧洞的特点,详细阐述了隧洞自身的防水质量控制及特殊形式外包井接头设计和施工技术,可为今后类似工程提供参考借鉴。