Flexing service schedules: Assessing the potential for demand-adaptive hybrid transit via a stated preference approach

This paper assesses the demand for a flexible, demand-adaptive transit service, using the Chicago region as an example. We designed and implemented a stated-preference survey in order to (1) identify potential users of flexible transit, and (2) inform the service design of the flexible transit mode. Multinomial logit, mixed-logit, and panel mixed-logit choice models were estimated using the data obtained from the survey. The survey instrument employed a d_p-efficient design and the Google Maps API to capture precise origins and destinations in order to create realistic choice scenarios. The stated-preference experiments offered respondents a choice between traditional transit, car, and a hypothetical flexible transit mode. Wait time, access time, travel time, service frequency, cost, and number of transfers varied across the choice scenarios. The choice model results indicate mode-specific values of in-vehicle travel time ranging between $16.3 per hour (car) and $21.1 per hour (flexible transit). The estimated value of walking time to transit is $25.9 per hour. The estimated value of waiting time at one’s point of origin for a flexible transit vehicle is $11.3 per hour; this value is significantly lower than the disutility typically associated with waiting at a transit stop/station indicating that the ‘at-home’ pick-up option of flexible transit is a highly desirable feature. The choice model results also indicate that respondents who use active-transport modes or public transit for their current commute trip, or are bikeshare members, were significantly more likely to choose flexible and traditional transit than car commuters in the choice experiments. The implications of these and other relevant model results for the design and delivery of flexible, technology-enabled services are discussed.     

大数据背景下的交通模型发展思考

将传统交通调查和模型与新的信息技术相结合,根据大数据的特征改进交通模型的方法体系,是交通模型发展面临的极大挑战.分析交通大数据对交通模型研发的促进作用,特别是在人口及就业岗位分布、综合交通网络数据和基于交通调查的模型参数等核心数据方面的支撑作用.从相关定义、市场细分以及信息完整性三个方面阐述大数据与交通模型的一致性问题.深入讨论应用大数据改进交通调查技术、4D模型研发、出行分布目的地选择模型、轨道交通出行接驳模型、出行成本校核等交通模型关键技术.通过对比大数据和交通模型的决策分析过程,指出大数据与交通模型互动发展的途径.     

Individual exposure to traffic related air pollution across land-use clusters

In this study, we estimated the transportation-related emissions of nitrogen oxides (NO_x) at an individual level for a sample of the Montreal population. Using linear regression, we quantified the associations between NO_x emissions and selected individual attributes. We then investigated the relationship between individual emissions of NO_x and exposure to nitrogen dioxide (NO₂) concentrations derived from a land-use regression model. Factor analysis and clustering of land-uses were used to test the relationships between emissions and exposures in different Montreal areas. We observed that the emissions generated per individual are positively associated with vehicle ownership, gender, and employment status. We also noted that individuals who live in the suburbs or in peripheral areas generate higher emissions of NO_x but are exposed to lower NO₂ concentrations at home and throughout their daily activities. Finally, we observed that for most individuals, NO₂ exposures based on daily activity locations were often slightly more elevated than NO₂ concentrations at the home location. We estimated that between 20% and 45% of individuals experience a daily exposure that is largely different from the concentration at their home location. Our findings are relevant to the evaluation of equity in the generation of transport emissions and exposure to traffic-related air pollution. We also shed light on the effect of accounting for daily activities when estimating air pollution exposure.     

Qualitative evaluation study of urban shared spaces in New Zealand

This paper presents the findings of a qualitative analysis using on-street perception and expert interview surveys of city centre streets that have been transformed into shared spaces in Auckland, New Zealand. The principal purpose was to investigate how well the shared streets performed, especially in relation to movement, access and place functions. The shared space sites at the Elliott, Lorne and Fort Street areas were measured against the performance criteria of Placemaking, Pedestrian Focus, Vehicle Behaviour Change, Economic Impetus and Safety for all users. On-street perception surveys totalling 360 responses (120 per site) were used in this study, together with an additional set of 40 responses from a survey of a control site in O’Connell Street that remained as a traditional street. Fifteen professionals with background in transportation and urban planning participated in semi-structured expert interviews. The main results of the Median Perception Ratings from the on-street surveys confirmed that the shared spaces generally performed positively. The statistical analysis revealed that the performance criteria of ‘Pedestrian’ and ‘Safety’ had a commanding influence over the other performance measures, and with the interconnectivity of the five objectives the perceived success of the urban shared spaces.     

中国出租汽车运营特征及启示

驾驶员与企业关系、运输服务质量是出租汽车行业两大核心问题。基于2013年交通运输业经济统计专项调查数据、城市客运统计年报数据以及出租汽车GPS监控信息统计等多源数据,分析中国出租汽车客运系统运营特征。以中心城市、地级市和县级市划分出租汽车服务城市的规模,以单班车、双班车和三班车划分出租汽车运营模式,总结出租汽车运力投放、日均行驶里程、空驶率、日均载客次数、利润等运营规律。基于分析结果提出3点启示:出租汽车行业改革宜根据城市的不同规模、类型进行分类指导;统筹考虑需求与供给、新技术发展并统一服务标志;兼具公共交通与私人交通双重属性,运营模式可多元化。     

大城市公交评价指标体系和公交竞争力指数研究

公交评价指标研究一直是学界探讨的热点,然而已有研究侧重于从服务水平层面探讨公交的评价指标,无法全面、综合地反映公共交通发展状况。针对这一问题,从国家战略、交通规划、交通运作和乘客感受四方面出发构建城市公交评价指标体系,给出指标具体计算方法。对指标进行标准评分,进而构建公交竞争力指数及计算模型,便于从整体把握公共交通发展程度以及在同类城市间进行比较。最后,以北京、上海、广州3个超大城市为例,计算各指标评分及公交竞争力指数,结果与交通实际状况较为吻合,验证了评价方法的可靠性。     

大型深水物探船船型研究

介绍国际上大型物探船的船型发展情况及其主要作业特点。结合我国近年新建的大型物探船,分析该船型在总布置、性能指标、谐波控制、水下噪声等方面的技术难点。     

GPS实时动态差分技术在水平位移监测中的应用研究

随着工程规模的日益扩大,常见的水平位移监测方法在大面积测区的情况下面临诸多困难,不能满足周期性监测的需要,而GPS的实时差分技术方便、快捷,但是不能满足水平位移监测精度的要求。通过设计测量误差评估试验,采集数据并进行整理,应用数理统计理论,进行方差分析,研究增加平滑采集次数与点位中误差的关系以及如何提高测量精度,达到可以利用GPS实时动态差分技术进行水平位移监测的目的,并进行技术分析和理论研究。     

社区居民适宜步行距离阈值研究

为研究社区居民适宜步行距离阈值,在上海市进行小区内RP(Revealed Preference)调查,通过询问居民前往某处目的地的出行方式,实际测量居民住处到目的地的距离,得出步行距离;然后在虹桥火车站进行可接受步行时间的调查。综合步行距离和步行时间的数据,结合偏态分布与距离衰变方程的分析方法,得出适宜步行距离与步行使用率的关系式,并通过计算得到了距离阈值。结果表明,由可接受步行时间调查计算得到的极限步行距离阈值为1500m,适用于城市规划的整体设计阶段;由步行距离调查数据计算得到的极限步行距离阈值为950m,可用于具体功能区的选址及交通衔接方式的选取;选取步行累计使用率为10%时对应的步行距离787m为适宜步行的距离阈值。     

高速公路设计测量放样中的重点问题探讨

针对高速公路设计测量放样中应重点把握的主要问题提出了自己的观点,并对测量放样中存在的难点及成果检验给出了解决问题的思路和方法。