1,721,037 research outputs found
Transport policies, travel behavior, and sustainability: a comparison of Germany and the U.S.
No full textThis dissertation investigates the influence of transport policies on individual travel behavior in Germany and the U.S. In spite of increasing automobile use in both countries, Germany has been more successful than the U.S. in maintaining a more balanced, sustainable transport system. In 2002, Americans drove 125 percent more kilometers per capita than Germans. Walking, cycling, and public transport accounted for only 14 percent of all trips in the U.S., compared to 40 percent in Germany. Excessive reliance on the car is responsible for unsustainable trends such as environmental pollution, oil dependence, obesity, traffic congestion, and road fatalities. In 2005, urban transport energy use and CO2 emissions per capita were three times higher in the U.S. than in Germany.
This analysis contains two parts capturing the interdependencies of transportation policies and individual travel decisions. A descriptive and qualitative examination of differences in travel trends and transport policies over time sets the frameworks within which individuals make daily travel choices in each country. A multivariate analysis based on two comparable national travel surveys then explores the intricacies of these choices.
The analysis shows that policies and institutions in the U.S. contribute to making car use cheaper, easier, and more common than in Germany. In 2005, for example, revenues from roadway user taxes and fees in Germany were 2.6 times larger than roadway expenditures by all levels of government, compared to net subsidies for roadways in the U.S. Unlike the majority of American cities, most German municipalities promote non-automobile travel and impose restrictions on driving, thus making car travel slower and less attractive. In 2002, average car travel speeds in the U.S. were 33 percent faster than in Germany. Multivariate analyses showed that transportation policies accounted for up to 25 percent of the variability explained in travel behavior.
Several policy recommendations follow from this research. First, higher population density, a greater mix of land uses, access to public transportation, and higher gasoline prices reduce car travel. Second, higher car-ownership rates and faster average car travel speeds increase car use. Lastly, the combination of car-restrictive policies with measures that increase the attractiveness of non-automobile modes has been key to more limited car use in Germany.Ph.D.Includes bibliographical references (p. 479-498)
Description of a model based bicycle simulator
No full textRecent years have seen an increase in cycling as a transport mode in urban centers. This has spurred an interest in the use of bicycle simulators to study cyclist behavior [1, 2, 3, 4]. However, few implement a model based approach that couples the bicycle roll and steer in a realistic manner [5]. Balancing is a key task in cycling and we aimed to develop a simulator that allows us to study the effect of balance on the rider’s higher level cognitive decisions.Biomechatronics & Human-Machine ControlIntelligent Vehicle
Cyclists’ predictions of what a car driver will do next at intersections
No full textIn the Netherlands, 30% of fatal crashes between 2010 and 2015 involved a cyclist [1], with a large portion of these crashes occurring at intersections in urban areas. Contributing factors to driver-cyclist collisions at intersections are not only inadequate visual search, but also incorrect expectations about the other’s intentions [2]. Research also suggests that crashes between drivers and cyclists often happen even when the cyclist must have seen the approaching car [2].The ability to anticipate future events is crucial for safe performance in traffic [3]. Recently, research has started on hazard anticipation in cycling. For example, an experiment using a hazard perception test has found that adult cyclists detect hazards earlier than children [4]. Furthermore, results from an eye-tracking experiment using animated video clips showed that cyclists are more likely to look at an approaching car (e.g., a car on a collision course) than to a car that has stopped before the intersection or a car that has passed the intersection [5]. However, it is unknown at which point in time and based on which visual cues a cyclist can predict that a perceived hazard becomes an actual hazard (i.e., that the car driver will not yield to a cyclist).We developed a video-based survey with the aim to gain an understanding of cyclists’ predictions in hazardous intersection situations. The following research questions were addressed herein:(1) How do cyclists’ predictions of the behavior of a car change in the moments prior to a crash or near miss with that car?(2) Is there a difference in cyclists’ predictions of the car’s behavior between crash and near miss scenarios?Biomechatronics & Human-Machine ControlTransport and Plannin
Determining the necessary width of a bicycle lane by means of simulations on a bicycle-rider model.
No full textIt can be observed that there is a wide variety in the width of bicycle lanes. It can range from wide to very narrow, see figure 1. Several guidelines disagree on the desired width of a bicycle lane [1, 2]. These guidelines are mainly based on observations and best practices. Instead of such an evolutionary approachwe propose to determine the necessary width by means of a scientific approach. We hypothesize that the dynamic properties of the bicycle together with the rider control determine the needed width of the bicycle lane. The inherent lateral instability of the bicycle with fixed steer input results in unavoidable lateral contact point displacements to keep the bicycle upright. Additionally, think of the necessary act of counter-steering to change heading direction.Biomechatronics & Human-Machine Contro
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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