Activity sequencing,location, and formation of individual non-mandatory tours: application to the activity-based models for Columbus,Cincinnati, and Cleveland,OH

Most of the earlier activity based models (ABMs) largely relied on a tour-based modeling paradigm which explicitly predicts tour frequency and then adds details including stop frequency, order, and location of stops within each tour. The current study is part of new tour formation design framework for an ABM in which the underlying tour structure and the stop frequency within tours emerge from temporal, sequencing, and locational preferences of activities that the traveler intends to participate during the day. In order to do this, the study developed a modified rank-ordered logit (ROL) framework that is capable of modeling sequence, locations, as well as the underlying tour structure of all activity episodes simultaneously in an integrated manner. Model estimation with the household survey data, provided several important behavioral insights into underlying choices that drive tour formation. Specifically, the study uncovered pairwise ordering preferences among episodes of different activity purposes, clustering tendencies among episodes of same activity purpose, the impact of supply side activity opportunities on the location and sequence choice dimensions, and impedance effects (including distance and mode and time-of-day logsums) on location and tour break dimensions. The developed models are incorporated in the operational ABM structure adopted for three major cities (Columbus, Cleveland, and Cincinnati) in Ohio.     

井喷的悲剧

导航电子地图的竞争点,从导航里程到POI（兴趣点）数量、然后再到电子眼提示功能……近期,3D导航界面的宣传风头初露．但也只不过是实现了路口放大和极少复杂路口假3D仿真。中国地域广阔．建筑多而杂,真正3D导航时代在中国为时尚早。那么。中国地图商们将赋予产品什么样的卖点来吸引更多的用户呢？我认为融入动态交通信息和道路救援系统．即将成为导航电子地图的重要卖点,也是“真正拉开产品差异、一比产品高下”时代的来临。     

Exploring traffic flow databases using space-time plots and data cubes

Local departments of transportation and metropolitan planning organizations have been collecting traffic data for many decades. However, these data are rarely exploited to their full potential. In this paper, we describe an exploratory visualization toolkit for large traffic flow databases. The visualization toolkit is based on the concept of the traffic cube: an extension of the data cube in data mining. The traffic cube organizes traffic flow data across different spatial and temporal dimensions and with respect to user-specified aggregation levels. The toolkit allows the user to perform data cube operations to select, summarize and cross-tabulate the traffic data prior to visualization as two-dimensional space-time plots. We demonstrate a prototype system using MATLAB, ArcGIS and MS Access database software. Example visualizations of a large database of hourly traffic flows along major highways in the state of Utah (USA) over a 10-year period illustrate the potential for the toolkit to reveal patterns about traffic flows and trends hidden in the database.     

An empirical analysis of freight transport traffic modes in Brazil, 1996–2012

This paper analyses the performance of freight transportation modes in Brazil – namely air, water, rail and road – from February 1996 to August 2012 by investigating their long memory properties using fractional integration and autoregressive models on monthly tonnage data. Two important features are analysed: the degree of dependence of transportation traffic across time and its seasonal structure over the period. Furthermore, the stability of parameters across the sample period is investigated, incorporating potential structural breaks in the data, which describe discontinuity in freight transportation traffic. Some policy implications are derived.     

An investigation of commuting trip timing and mode choice in the Greater Toronto Area: Application of a joint discrete-continuous model

The trip timing and mode choice are two critical decisions of individual commuters mostly define peak period traffic congestion in urban areas. Due to the increasing evidence in many North American cities that the duration of the congested peak travelling periods is expanding (peak spreading), it becomes necessary and natural to investigate these two commuting decisions jointly. In addition to being considered jointly with mode choice decisions, trip timing must also be modelled as a continuous variable in order to precisely capture peak spreading trends in a policy sensitive transportation demand model. However, in the literature to date, these two fundamental decisions have largely been treated separately or in some cases as integrated discrete decisions for joint investigation. In this paper, a discrete-continuous econometric model is used to investigate the joint decisions of trip timing and mode choice for commuting trips in the Greater Toronto Area (GTA). The joint model, with a multinomial logit model for mode choice and a continuous time hazard model for trip timing, allows for unrestricted correlation between the unobserved factors influencing these two decisions. Models are estimated by occupation groups using 2001 travel survey data for the GTA. Across all occupation groups, strong correlations between unobserved factors influencing mode choice and trip timing are found. Furthermore, the estimated model proves that it sufficiently captures the peak spreading phenomenon and is capable of being applied within the activity-based travel demand model framework.     

健美冠军Ford Mustang Shelby GT500

福特野马Shelby GT500继承了原型车全面高性能的传统,正是这种特质使GT500的原型赛车称雄于世界各地的赛场和公路比赛。     

一脉相承Audi TT Roadster

奥迪宣布了第二代TT敞蓬跑车的诞生。新车依旧传承了上一代TT时尚圆润的造型风格,折叠车顶仍然坚持使用软质布顶,好处是减少整备质量的同时又降低了重心高度。     

休闲运动Renault Megane GT

雷诺旗下主力产品Megane自从发表新一代车型以来．凭借着许多独特的设计手法,不但赢得全球车迷们的目光,还确立了这家法国车厂新时代的家族造型风格,而近年来雷诺在F1赛场上的优异表现．更让其拥有鲜明的运动形象．除了国人较为熟悉的MeganeRS225之外．原厂在日前也发表了同样具有运动取向的MeganeGT．以巩固其在市场上的地位。该款车定位介于一般版本的Megane以及由雷诺运动部门所开发的产品之间。同时．为了满足客户的不同需求．MeganeGT将同时有三门和五门两种车型。     

不容小视的新手Hyundai Veracruz

维拉克斯是现代汽车全新打造的豪华SUV。维拉克斯从2004年7月开始研发,历时26个月耗资2亿2200万美元,以时尚动感的设计,大量的尖端技术,最完备的安全系统和各种人性化的便利配置融为一体。并寄予着提升现代汽车品牌的全新产品。