基于希尔伯特指标空间的出行方式安全评价

以道路交通危险要素为基础,结合城市道路及其管理控制情况,对城市道路不同出行方式的安全影响因素进行分析,构建评价指标体系,并运用泛函理论建立希尔伯特指标空间。然后运用模糊数学基本理论所具有的将模糊信息定量化和复杂性强的特性,对出行方式安全等级进行评价。最后就公交出行方式的安全等级评定给出算例,以验证评价方法的合理有效。     

Transportation impacts of center-based telecommuting: Interim findings from the Neighborhood Telecenters Project

The transportation impacts of center-based telecommuting for 24 participants (representing 69 person-days of travel and 295 trips) in the California Neighborhood Telecenters Project are analyzed. Comparing non-telecommuting (NTC) day to telecommuting (TC) day travel shows that person-trips did not change significantly, whereas vehicle-trips increased significantly (by about one trip) on TC days. Both PMT and VMT decline significantly on TC days: by an average of 68 miles (74%) and 38 miles (65%), respectively. When these savings are weighted by the frequency of telecommuting, overall reductions in PMT and VMT come to 19% and 17%, respectively, of total weekday travel. Commute trips increase slightly (by 0.5 trips) but significantly, mainly due to lunch-time trips made home from the telecenter. Total non-commute travel does not increase, but there is a significant shift from other modes to driving alone on TC days. Commute mode split on NTC days is not affected by telecommuting. Travel on TC days tends to be compressed into fewer hours. Higher numbers of return home, eat meal, shopping, and social/recreational trips are made on TC days, in exchange for a reduction (to zero) in the number of change mode trips.     

Running for the 7:45: The effects of public transit improvements on commuter stress

This research project took advantage of the implementation of a major mass transit improvement by New Jersey Transit which provided a "one-seat ride" into New York City for many commuters who previously had to transfer in Hoboken in order to take Port Authority Trans Hudson (PATH) trains into New York City. The creation of this new service provided a natural experiment in which some riders switched to the new route, while others continued to use their previous route. We studied psychological and psychophysiological responses to these commuting options, using a quasi-experimental, pre-post change, field research design.We found that riders on this new line had lower levels of stress, as multiply measured, than they had earlier, before the advent of this new train, or than did other riders currently using the Hoboken-PATH option. The stress effects seemed to be mediated by the time of the trip – that is, the reduced trip time of the new, direct service seemed to be a primary factor in the reduced stress to riders. Predictability of the trip was also inversely correlated with stress, but did not distinguish between the commuter groups. These results were largely replicated with a student group who rode the same lines acting as simulated commuters.     

The positive utility of the commute: modeling ideal commute time and relative desired commute amount

Two measures of commute time preferences – Ideal Commute Time and Relative Desired Commute amount (a variable indicating the desire to commute "much less" to "much more" than currently) – are modeled, using tobit and ordered probit, respectively. Ideal Commute Time was found to be positively related to Actual Commute Time and to a liking and utility for commuting, and negatively related to commute frequency and to a family/community-oriented lifestyle. Relative Desired Commute, on the other hand, was negatively related to amounts of actual commute and work-related travel, but positively related to travel liking and a measure of commute benefit. Overall, commute time is not unequivocally a source of disutility to be minimized, but rather offers some benefits (such as a transition between home and work). Most people have a non-zero optimum commute time, which can be violated in either direction – i.e. it is possible (although comparatively rare, occurring for only 7% of the sample) to commute too little. On the other hand, a large proportion of people (52% of the sample) are commuting longer than they would like, and hence would presumably be receptive to reducing (although usually not eliminating) that commute.     

基于随机用户平衡的混合交通网络流量分离模型

考虑了影响出行者交通选择行为的主要因素(时间、费用、方便性、舒适性等),分析了在多种交通方式(私家车、出租车、公交车、轨道交通以及自行车等)存在条件下城市交通网络中出行者交通选择行为,包括交通方式选择和出行路径选择,并基于随机用户平衡(SUE)理论构造了城市混合交通网络的流量分离和分配综合模型及求解算法。最后通过一个简单算例,得到了当各种影响因素变化时,各种交通方式的流量变化情况。     

汽车滚翻事故的再现分析方法

汽车滚翻事故的再现分析是一个复杂的过程,需要仔细考察汽车滚翻过程的3个阶段,包括侧滑阶段、侧翻阶段和翻滚阶段.论述了各阶段再现分析常用的模型和方法,介绍了一般计算方法或再现步骤,以及二维和三维再现的目标和技术要点,使用计算机辅助事故再现.再现分析滚翻事故中汽车运动过程及其瞬时速度和空间姿态,能够为事故处理和责任认定提供科学依据,并有助于改进车身机构和车内被动安全装置的设计.     

居民出行方式选择非集计模型的建立

基于非集计离散选择模型的基本理论与建模方法,结合2003年北京居民出行调查数据,对影响居民出行方式选择的因素进行了分析,选择包括公交车、出租车、私人小汽车等在内的5种日常生活中较为常用的交通方式作为居民出行的方式选择肢,确定了影响居民出行方式选择的特性变量及相应的取值方法,建立了交通方式选择MNL模型。应用Matlab优化工具箱中的无约束最优化函数对所建的MNL模型的参数进行了标定,并通过命中率的计算验证了模型的有效性。结果表明,非集计建模方法能够较全面的考虑居民出行选择的各方面影响因素,尤其是将出行者的个人特性影响因素引入模型,提高了模型的预测精度和实用性。     

北京市住宅建筑交通出行率研究

针对目前我国城市建筑项目交通影响评价中缺乏交通出行率指标的现状,参考美国等发达国家对土地使用及交通出行率的研究方法,在对北京市城区范围内334个住宅小区进行交通出行率调查的基础上,应用相关度分析方法确定了出行率重要相关参数,并分别用平均生成率法、参考调查点法（图表法）以及回归分析方法对调查数据进行了分析和处理,初步得到了北京市住宅建筑出行率指标的建议取值标准。本文建立的方法可用于城市其他类别建筑项目交捅出行率调杏和分新处理工作．所梧出的居住娄王聿笛．交踊出行率指标值可供城市交通影响评价工作参考。     

不同类型社区居民特征与居民通勤碳排放的关系

为了探究居民特征对居民通勤碳排放分布的影响,对西安市不同类型的8 个社区进行了 居民出行调查。通过计算居民的通勤碳排放和统计各类居民个人特征,分析了各社区内产生通 勤碳排放较高的居民组成。研究结果表明：本科学历、公司职员、41~50 岁是最可能产生高碳 排放的居民特征,但在不同类型的社区中分布情况有明显差异;同类型的社区,距离市中心越 远,居民越可能产生高碳排放,但高碳排群体的特征与社区位置无关;不同类型社区对应不同 类型的居民群体,而具有相似特征的居民的出行选择也较为相近,使得碳排放的分布与居民特 征密切相关。     

Comparison of pedestrian trip generation models

Using Poisson regression and negative binomial regression, this paper presents an empirical comparison of four different regression models for the estimation of pedestrian demand at the regional level and finds the most appropriate model with reference to the National Household Travel Survey (NHTS) 2001 data for the Baltimore (USA) region. The results show that Poisson regression seems to be more appropriate for pedestrian trip generation modeling in terms of χ² ratio test, Pseudo R², and Akaike's information criterion (AIC). However, R² based on deviance residuals and estimated log‐likelihood value at convergence confirmed the empirical studies that negative binomial regression is more appropriate for the over‐dispersed dependent variable than Poisson regression. Copyright © 2011 John Wiley & Sons, Ltd.