In recent years, bikeshare systems have spread throughout the United States. Despite the increase in systems and users, little is known about how bikeshare member demographics and travel patterns compare with those of traditional bicyclists. To bridge the gap, this study investigated bikeshare system user travel behavior and developed a profile of user demographics through the comparison of short-term (1 day) users and annual members of Capital Bikeshare (CaBi) in Washington, D.C., with profiles of area bicyclists. Data originated from a Washington, D.C., regional household travel survey of 2007-2008, an intercept survey of short-term CaBi users, and an online survey of annual CaBi members. The analysis compared gender, race and ethnicity, age, and student status, as well as socioeconomic status across the surveys. The comparison included trip purpose, helmet use, and travel modes for trips that were replaced by bikesharing. Profiles of CaBi and area cyclists differed with respect to many demographic and socioeconomic characteristics. Compared with area cyclists, CaBi short-term users and annual members were more likely to be female and younger, to have lower household incomes, and to own fewer cars and fewer bicycles and were more likely to cycle for utilitarian purposes. CaBi trips mainly replaced trips made by public transport and by walking. CaBi short-term users and members shared similar characteristics, but short-term users were more likely to ride for recreational purposes and were less likely to wear a helmet. The study results indicated that bikesharing can encourage new segments of society to cycle and can help increase the bicycling mode share overall.

关键词：大气；自行车；空气保护

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Rear-end crashes on freeways contribute significantly to nonrecurring congestion. Reducing these events would significantly improve freeway capacity, particularly during peak hours. Although promising coun-termeasures, such as variable speed limits, changeable message signs, and vehicle-based improvements, are under consideration, currently there is a shortage of demonstrably proven countermeasures targeted at freeway rear-end crashes. Liability rules, in which the direct cost associated with a crash is divided between the drivers, their insurance companies, or both, are a primary mechanism for influencing the occurrence of freeway rear-end crashes. An exploratory effort uses concepts from evolutionary game theory to predict the effects of liability rules on rear-end crashes. In a typical two-vehicle car-following scenario, driving behavior can be associated with a utility that each driver expects to achieve depending on his or her and the opponent's actions. Such interactions between leader and follower are modeled as the outcome of an evolutionary process in which drivers with different driving behaviors are randomly and repeatedly matched against each other to play a two-player game. The outcome of these games determines the fraction of drivers pursuing a particular driving strategy for the next phase of the game. The stable long-run distribution of driving strategies is then used to predict the proportion of drivers who are more likely to be involved in a rear-end accident. It turns out that when direct crash costs are allocated evenly to the involved drivers, a population in which all drivers act to avoid crashes is not evolutionarily stable.

关键词：汽车；交通拥挤；博弈论

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The driver-specific data available from naturalistic driving studies provide a unique perspective from which to test and calibrate car-following models. As equipment and data storage costs continue to decline, the collection of data through in situ probe-type vehicles is likely to become more popular, and thus there is a need to assess the feasibility of these data for the modeling of driver car-following behavior. This study focused on the costs and benefits of naturalistic data for use in mobility applications. Any project seeking to use naturalistic data should plan for a complex and potentially costly data reduction process to extract mobility data. A case study was based on data from the database of the 100-Car Study conducted by the Virginia Tech Transportation Institute. One thousand minutes' worth of data comprising more than 2,000 car-following events recorded across eight drivers from a section of multilane highway located near Washington, D.C., was compiled. The collected event data were used to calibrate four different car-following models, and a comparative analysis of model performance was conducted. The results of model calibration are given in tabular format, displayed on the fundamental diagram, and shown with sample event charts of speed versus time and headway versus time. When compared with the Gipps, intelligent driver, and Gaxis-Herman-Rothery models, the Rakha-Pasumarthy-Adjerid model was found to perform best in matching individual drivers and in matching aggregate results.

关键词：汽车；跟车行为；数据建模

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The Netherlands is well known for its large share of bicycle use and for its relatively compact cities; these conditions suggest that transport poverty may be less of a problem than in other developed countries. This paper explores the role of the bicycle in the avoidance of transport poverty on the basis of two exploratory studies. The first study focused on low-income households and showed that the bicycle did curb transport poverty but was of limited importance as a means of access to the labor market. The second study explored the ability of households without cars to maintain social networks. The study findings underlined the importance of the bicycle but also showed that the bicycle was used selectively by elderly residents and was of limited relevance to households with a social network that extended beyond urban borders.

关键词：汽车；自行车；角色

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Mobility attributes such as driver's license, car ownership, reserved parking at work, and transit pass have a very strong impact on travel choices, in particular, mode choice. Mobility attributes are not acquired for a particular trip but rather are driven by the entire set of individual travel needs (commuting being the most basic of them). Some mobility attributes, for example, car ownership and transit pass, are substitutable; others, for example, car ownership and reserved parking at work, are complementary. For this reason, mobility attributes have to be analyzed and modeled jointly. The purpose of the current research is to analyze a wide set of mobility attributes and incorporate them in an operational activity-based model as a set of midterm choices. The approach suggested in this paper is based on an iterative application of three interlinked choice submodels: (a) joint choice of person driver's license, usual driver role (priority in using one of the household cars), car type choice, reserved or reimbursed parking at work, and transit pass; (b) household car ownership choice by type; and (c) intrahousehold car allocation by type. Model estimation results confirmed strong cross-attribute effects as well as revealed many impacts of person, household, and travel accessibility variables. In particular, historical and cultural differences between three population sectors in Jerusalem-secular Jewish, Orthodox Jewish, and Arab-manifested themselves quite strongly. Application of these models for future scenarios is discussed.

关键词：汽车；设计风格；个性化

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报告从行业事件分析、政策环境、市场环境、旅游交通、国际环境等相关行业数据方面进行了分析评论。

关键词：政策环境；市场环境；旅游交通；国际环境

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关键词：汽车；管理维护；交通成本

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A comprehensive benefit-cost assessment of motorcycle use is offered, along with the characteristics, behaviors, and attitudes of motorcycle riders. U.S. motorcyclists are at high risk of crashing, with rates 24 times higher than those of passenger car and light-duty truck drivers per mile traveled. However, motorcycles require only one-quarter the parking space of a car and can reduce congestion by doubling network capacity (in vehicles per hour). Most motorcycles have high fuel economy, but low seating capacities render them little or no better than most cars and some light-duty trucks (assuming average vehicle occupancies) when compared in terms of fuel consumption per rider (or vehicle occupant) mile traveled. Motorcycles emit fewer grams of many polluting emissions but more volatile organic compounds and carbon monoxide than most cars if a catalytic converter is not installed. Noise impacts are a serious issue, with an inconsistent patchwork of regulations applied across states and localities. Results of a survey of current and former U.S. motorcyclists indicate that most respondents ride motorcycles for recreational purposes and ride in groups, but about one-half also ride for more mandatory (less discretionary) purposes and about 40% also ride solo. Fewer than one-third of respondents have formal motorcycle training, and helmet use is lowest among current riders who do not own a motorcycle. Engine size appears to be rising, and respondents support policies that combat operating a vehicle under the influence (e.g., ignition interlock devices for offenders). Regression models illuminate key factors and marginal effects on motorcycle riding and ownership rates.

关键词：汽车；评估成本；效益

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Analysys 易观智库将电子商务B2B 业务定义为：以电子商务B2B 平台以及大数据为基础，通过整合产业链上下游资源完成企业与企业之间的营销关系的电子商务活动，包括信息与交易服务、商业搜索引擎服务、金融服务、云端服务等。

关键词：电子商务；B2B；市场分析

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An application of the basic results of deterministic network calculus theory to road traffic flow theory is presented. Network calculus is a theory based on min-plus algebra. This calculus uses algebraic techniques to compute performance bounds in communication networks, such as maximum end-to-end delays and backlogs. The objective of this paper is to investigate the application of those techniques for determining performance bounds on road networks, such as upper bounds for travel times. A traffic model is proposed for cars moving in a single-lane ring road without passing. The model is compatible with network calculus theory and permits derivation of an upper bound of the travel time of cars on the road. An approach for extending the model to calculate upper bounds for the travel times of cars on paths passing through intersections in a whole network is also proposed.

关键词：汽车；交通网络；微积分

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