The impact of urban form on automobile travel: disentangling causation from correlation

A longstanding question within the field of transportation demand management is the strength of the relationship between urban form and mobility behavior. Although several studies have identified a strong correlation between these variables, there is as yet scant evidence to support policy interventions that target land use as a means of influencing travel. To the contrary, some of the more recent research has cast skepticism on the proposition that the relationship is causative, recognizing the possibility that households endogenously self-select themselves into communities that support their preferences for particular transportation modes. Focusing on individual automobile travel, the present study seeks to contribute to this line of inquiry by estimating econometric models on a panel of travel-diary data collected in Germany between 1996 and 2003. Specifically, we employ the two-part model (2PM)—a procedure involving probit and OLS estimators—to assess the determinants of the discrete decision to use the car and the continuous decision of distance traveled. Beyond modeling variables that capture the urban form features that are commonly suggested to influence mobility behavior, including mixed use and public transit, this study employs instrumental variables to control for potential endogeneity emerging from the simultaneity of residential and mode choices. Unlike much of the work to date, our results suggest that urban form has a causative impact on car use, a finding that is robust to alternative econometric specifications.

城市轨道交通乘客信息服务系统数据结构分析

在对城市轨道交通乘客信息服务的需求分析基础上,提出单一线路轨道交通乘客信息服务系统的通用数据结构,为基于不同的信号系统数据建立乘客信息服务系统的设计提供一个跨信号系统和计算机信息系统的数据构造方案.     

贝雷法混合料级配设计原理及级配特征

介绍了美国Robert D.Bailey先生发明的一种确定沥青混合料级配的一种方法,重点讲述了其主要设计思想和数学模型。