Modeling the choice continuum: an integrated model of residential location,auto ownership,bicycle ownership,and commute tour mode choice decisions

The integrated modeling of land use and transportation choices involves analyzing a continuum of choices that characterize people’s lifestyles across temporal scales. This includes long-term choices such as residential and work location choices that affect land-use, medium-term choices such as vehicle ownership, and short-term choices such as travel mode choice that affect travel demand. Prior research in this area has been limited by the complexities associated with the development of integrated model systems that combine the long-, medium- and short-term choices into a unified analytical framework. This paper presents an integrated simultaneous multi-dimensional choice model of residential location, auto ownership, bicycle ownership, and commute tour mode choices using a mixed multidimensional choice modeling methodology. Model estimation results using the San Francisco Bay Area highlight a series of interdependencies among the multi-dimensional choice processes. The interdependencies include: (1) self-selection effects due to observed and unobserved factors, where households locate based on lifestyle and mobility preferences, (2) endogeneity effects, where any one choice dimension is not exogenous to another, but is endogenous to the system as a whole, (3) correlated error structures, where common unobserved factors significantly and simultaneously impact multiple choice dimensions, and (4) unobserved heterogeneity, where decision-makers show significant variation in sensitivity to explanatory variables due to unobserved factors. From a policy standpoint, to be able to forecast the “true” causal influence of activity-travel environment changes on residential location, auto/bicycle ownership, and commute mode choices, it is necessary to capture the above-identified interdependencies by jointly modeling the multiple choice dimensions in an integrated framework.     

Residential mobility and location choice: a nested logit model with sampling of alternatives

Residential mobility and relocation choice are essential parts of integrated transportation and land use models. These decision processes have been examined and modeled individually to a great extent but there remain gaps in the literature on the underlying behaviors that connect them. Households may partly base their decision to move from or stay at a current location on the price and quality of the available alternatives. Conversely, households that are on the market for a new location may evaluate housing choices relative to their previous residence. How and the degree to which these decisions relate to each other are, however, not completely understood. This research is intended to contribute to the body of empirical evidence that will help answer these questions. It is hypothesized that residential mobility and location choice are related household decisions that can be modeled together using a two-tier hierarchical structure. This paper presents a novel nested logit (NL) model with sampling of alternatives and a proposed procedure for sampling bias correction. The model was estimated using full-information maximum likelihood estimation methods. The results confirm the applicability of this NL model and support similar findings from other empirical studies in the residential mobility and location choice literature.     

A practical method to estimate the benefits of improved road network reliability: an application to departing air passengers

This paper develops and applies a practical method to estimate the benefits of improved reliability of road networks. We present a general methodology to estimate the scheduling costs due to travel time variability for car travel. In contrast to existing practical methods, we explicitly consider the effect of travel time variability on departure time choices. We focus on situations when only mean delays are known, which is typically the case when standard transport models are used. We first show how travel time variability can be predicted from mean delays. We then estimate the scheduling costs of travellers, taking into account their optimal departure time choice given the estimated travel time variability. We illustrate the methodology for air passengers traveling by car to Amsterdam Schiphol Airport. We find that on average planned improvements in network reliability only lead to a small reduction in access costs per trip in absolute terms, mainly because most air passengers drive to the airport outside peak hours, when travel time variability tends to be low. However, in relative terms the reduction in access costs due to the improvements in network reliability is substantial. In our case we find that for every 1 Euro reduction in travel time costs, there is an additional cost reduction of 0.7 Euro due to lower travel time variability, and hence lower scheduling costs. Ignoring the benefits from improved reliability may therefore lead to a severe underestimation of the total benefits of infrastructure improvements.     

Evaluating Boating Safety Risk in Intracoastal Waterways

Growth in the number of recreational vessels that use inland and coastal waterways, coupled with the diversity of boating activities, results in increased boating-related conflicts, accidents, and fatalities. This situation has led to numerous requests from boaters, shorefront property owners, waterfront businesses, and local governments for the imposition and enforcement of boating safety speed zones within Florida's Intracoastal Waterways. A decision-support framework that incorporates Geographic Information Systems (GIS)–based risk assessment was developed to assist the Florida Fish and Wildlife Conservation Commission's Division of Law Enforcement evaluate requests and applications for the establishment of boating safety zones, pursuant to the Florida Administrative Code Rule 68-D-23.105 “Criteria for Approval of Regulatory Markers.” The risk assessment uses geospatial data compiled from multiple government agencies, survey data from subject matter experts, and public input from participatory workshops. Relevant spatial data includes waterway features and marine infrastructure from field surveys, vessel traffic patterns observed and mapped from aerial reconnaissance, and indicators of boater behaviors extracted from accident and citation reports. The outcome is a characterization of waterway segments according to perceived risk to boating safety. The application was tested in two Florida counties and it helped guide the establishment of new, and the revision of existing, boating regulatory zones within their Intracoastal Waterways. The application design is such that it is adaptable to waterways beyond those in Florida.     

American Samoa: Establishing a coastal area management model for developing countries

Abstract

Debate over the appropriateness of U.S. approaches to coastal management procedures for developing countries has increased over the past few years. The coastal management program which was developed for American Samoa offers the opportunity to test the utility of the U.S. approach to CZM for developing nations.

American Samoa represents a blend of traditional and new cultures and thus may be a microcosm of developing countries. American Samoa's development of a CZM plan is examined with emphasis on similarities and differences with U.S. experience. A culture‐oriented framework is presented which can shape programs appropriate to developing countries. Finally, a process and a set of guidelines provide an outline for those attempting the difficult task of applying U.S. environmental planning and management to other countries.     

中文文字的计算

中文文字是世界上最古老、使用最广泛的文字，语义丰富，而且可与计算机完美地结合．文字计算可以也应该应用中文文字，以便获得更广泛的应用价值．模糊逻辑为中文文字的形式化提供了一种有效的方法．现在是开展中文文字计算研究的大好时机，并能为投资者提供巨大商机．     

Optimizing the transportation of international container cargoes in Korea

This paper considers a multimodal transportation problem, which is the problem of determining the transportation flow, i.e. volume of container cargoes, and the transportation mode in each trade route, for the objective of minimizing the sum of shipping and inland transportation costs. The problem takes account of two restrictions: maximum cargo volumes capacitated at each seaport and maximum number of vehicles available at each transportation mode. To solve optimally the problem, this paper employs a mixed integer programming, which is an operations research technique. A case study is performed on the container cargo data in Korea and we draw several implications to improve efficiency in the transportation of international trade cargoes in Korea.     

自动化实时监测系统在中国台湾高速铁路浅埋隧道的应用

中国台湾高速铁路新竹二高隧道以覆土深度9～12m穿越台湾北部第二高速公路。为了考虑高速公路下方隧道穿越施工时的行车安全,采用自动化监测系统,监控隧道施工产生之顶部路面沉降与隧道侧墙土层之变位。监测系统采用捷仪工程科技公司GeoAuto自动化实时监测软件系统,该系统分前端、中端、后端三部分。前端部分在隧道顶部沿隧道方向安装有自动量测水平倾斜计、在隧道两侧各安装有自动量测垂直倾斜计与伸张仪,另沿高速公路方向安装3排路面沉降点以全站仪自动监测,前述各类仪器皆连接至资料集录器;中端部分为ADSL、直接联机与无线传输等方式进行数据传输;后端部分为GeoAuto自动监测软件系统,所有路面沉降、土层变位等现场数据,皆由前端仪器量测、经中端传输,最后将所有现场有关沉降、变位等数据,皆显现于后端电脑显示器上。在自动监测系统配合下,有效协助浅埋隧道凿进,顺利完成隧道施工。     

Transport models, philosophy and language

The aim of this paper is to encourage debate about the nature of transport modelling. It does so firstly by considering the underlying philosophies of science (apparently) adopted by transport modellers, over a period of more than 50 years, from the 1950s until the present day. The conclusion is that a new philosophy of science needs to be developed, which is more in tune with how transport modelling is actually carried out (as opposed to how early transport modellers thought it ought to be carried out). It is recommended that such a new philosophy perceives transport modelling as a linguistic activity within the overall context of transport planning, which is in turn considered as a communication process. The paper outlines three main approaches that could be taken in this respect, analysing transport models from metaphorical, narrative and aesthetic perspectives. Conclusions are drawn upon the possible future research directions that might follow from the analysis provided in the paper, emphasising the importance of bringing formal philosophical thinking into transport modelling research and practice.