410 research outputs found

    Attracting and Retaining Women in the Transportation Industry

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    This study synthesized previously conducted research and identified additional research needed to attract, promote, and retain women in the transportation industry. This study will detail major findings and subsequent recommendations, based on the annotated bibliography, of the current atmosphere and the most successful ways to attract and retain young women in the transportation industry in the future. Oftentimes, it is perception that drives women away from the transportation industry, as communal goals are not emphasized in transportation. Men are attracted to agentic goals, whereas women tend to be more attracted to communal goals (Diekman et al., 2011). While this misalignment of goals has been found to be one reason that women tend to avoid the transportation industry, there are ways to highlight the goal congruity processes that contribute to transportation engineering, planning, operations, maintenance, and decisions—thus attracting the most talented individuals, regardless of gender. Other literature has pointed to the lack of female role models and mentors as one reason that it is difficult to attract women to transportation (Dennehy & Dasgupta, 2017). It is encouraging to know that attention is being placed on the attraction and retention of women in all fields, as it will increase the probability that the best individual is attracted to the career that best fits their abilities, regardless of gender

    Oregon Freight Data Mart

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    Increasing freight volumes are adding pressure to the Oregon transportation system. Monitoring the performance of the transportation system and freight movements is essential to guarantee the economic development of the region, the efficient allocation of resources, and the quality of life of all Oregonians. Freight data is expensive to collect and maintain. Confidentiality issues, the size of the datasets, and the complexity of freight movements are barriers that preclude the easy access and analysis of freight data. Data accessibility and integration is essential to ensure successful freight planning and consistency across regional partner agencies and planning organizations. In relation to Internet-based mapping technology in freight data collection and planning, the main objectives of this project are: (a) address implementation issues associated with data integration, (b) present a system architecture to leverage existing publically-available interfaces and web applications to accelerate product development and reduce costs, (c) describe an existing web-based mapping prototype and its capabilities, (d) state lessons learned and present suggestions to streamline the integration and visualization of freight data, and (e) discuss load-time and display quality issues associated with the visualization of transportation data on internet-based mapping applications. The strategies and methodologies described in this report are equally applicable to the display of areas such as states or counties as well as linear data such linear data such as highways, waterways, and railways. Despite data integration challenges, Internet-based mapping provides a cost effective and appealing tool to store, access, and communicate freight data as well as enhance our understanding of freight issues. Institutional barriers, not technology, are the most demanding hurdles to widely implementing a freight data web-based mapping application in the near future

    Optimal Bus Stop Spacing for Minimizing Transit Operation Cost

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    With the increasing attention to finance issues relative to transit operation, a bus stop spacing model is generated with the aim at minimizing the operation cost without impact on transit accessibility. Two cost functions are considered in the model including passenger access cost and in-vehicle passenger stopping cost aiming at minimizing total cost. A bus route in Portland, Oregon, USA is examined as an example using Archived Bus Dispatch System (BDS) data provided by TriMet, the regional transit provider for the Portland, Oregon metropolitan area. Based on the optimization model, the theoretical optimized bus stop spacing is 930 feet comparing to the current value 802 feet

    Some observed queue discharge features at a freeway bottleneck downstream of a merge

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    Details of traffic evolution were studied upstream and downstream of a freeway bottleneck located near a busy on-ramp. It is shown that on certain days the bottleneck became active upon dissipation of a queue emanating from somewhere further downstream. On such occasions, the bottleneck occurred at a fixed location, approximately one kilometer downstream of the merge. Notably, even after the dissipation of a downstream queue, the discharge flows in the active bottleneck were nearly constant, since the cumulative counts never deviated much from a linear trend. The average bottleneck discharge flows were also reproducible from day to day. The diagnostic tools used in this study were curves of cumulative vehicle arrival number versus time and cumulative occupancy versus time constructed from data measured at neighboring freeway loop detectors. Once suitably transformed, these cumulative curves provided the measurement resolution necessary to observe the transitions between freely flowing and queued conditions and to identify some important traffic features

    Some traffic features at freeway bottlenecks

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    Observations from two freeway bottlenecks in and near Toronto, Canada indicate that the average rate vehicles discharge from a queue can be 10% lower than the flow measured prior to the queue\u27s formation. Absent any influences from downstream, the queue discharge flows exhibited nearly stationary patterns that alternated between higher and lower rates. These alternating flow patterns were especially evident at one of the two sites, although the feature occurred at both sites during periods that immediately followed the onset of upstream queuing; i.e. a queue\u27s formation was always accompanied by a relatively low discharge rate followed later by a temporary surge in the discharge flow. When plotted cumulatively over time, however, the counts of discharging vehicles generally did not deviate by more than about 50 vehicles from a trend line of constant slope. Thus, the discharge flows are described as being `nearly\u27 constant; i.e. they varied (slightly) about a fixed rate. At each site, this average discharge rate exhibited little deviation from day to day. The present findings came by visually comparing transformed curves of cumulative vehicle arrival number vs time and cumulative occupancy vs time measured at neighboring loop detectors. This treatment of the data provided clear presentations of some important traffic features and this facilitated a detailed study of bottleneck flows

    Possible explanations of phase transitions in highway traffic

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    It is shown that all the phase transitions in and out of freely flowing traffic reported earlier for a German site could be caused by bottlenecks, as are all the transitions observed at two other sites examined here. The evidence suggests that bottlenecks cause these transitions in a predictable way, and does not suggest that stoppages (jams) appear spontaneously in free flow traffic for no apparent reason. It is also shown that many of the complicated instability phenomena observed at all locations can be explained qualitatively in terms of a simple Markovian theory specific to traffic that does not necessarily include spontaneous transitions into the queued state as a feature

    Evolution and Usage of the Portal Data Archive: 10-Year Retrospective

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    The Portal transportation data archive (http://portal.its.pdx.edu/) was begun in June 2004 in collaboration with the Oregon Department of Transportation, with a single data source: freeway loop detector data. In 10 years, Portal has grown to contain approximately 3 TB of transportation-related data from a wide variety of systems and sources, including freeway data, arterial signal data, travel times from Bluetooth detection systems, transit data, and bicycle count data. Over its 10-year existence, Portal has expanded both in the type of data that it receives and in the geographic regions from which it gets data. This paper discusses the evolution of Portal. The paper describes the new data, new regions, and new systems that have been added and how those changes have affected the archive. The paper concludes with a section on the uses of Portal that provides several examples of how Portal data have been used by regional partners, with a focus on measuring the performance of the multimodal transportation system, but also including educational elements and research

    Seminar #294: Transforming Transportation Through Connectivity

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    The transportation system is the backbone of the United States\u27 economy, and transportation is an essential part of everyday life for American citizens. It is essential that the transportation system continue to provide accessibility and connectivity to an ever-evolving global economy. A key way to do so is to embrace, develop and implement new technologies. One of the newest and most promising facets of transportation-related technology is in the field of connected mobility. The vision behind connected mobility is of a transportation system where vehicles, travelers, and infrastructure are all wirelessly connected with one another and able to transmit real-time data about things like weather, location, and vehicle and infrastructure status. Such a degree of connectivity could have substantial benefits for the safety, mobility, and sustainability of the domestic transportation system, including accident prevention and congestion reduction. In recent years, major strides have been made into the research and development of connected mobility technology and some field-testing has commenced, but there is a need for more attention and investment from stakeholders throughout the transportation community and beyond.https://pdxscholar.library.pdx.edu/trec_seminar/1016/thumbnail.jp

    Dobrushin states in the \phi^4_1 model

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    We consider the van der Waals free energy functional in a bounded interval with inhomogeneous Dirichlet boundary conditions imposing the two stable phases at the endpoints. We compute the asymptotic free energy cost, as the length of the interval diverges, of shifting the interface from the midpoint. We then discuss the effect of thermal fluctuations by analyzing the \phi^4_1-measure with Dobrushin boundary conditions. In particular, we obtain a nontrivial limit in a suitable scaling in which the length of the interval diverges and the temperature vanishes. The limiting state is not translation invariant and describes a localized interface. This result can be seen as the probabilistic counterpart of the variational convergence of the associated excess free energy.Comment: 34 page
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