23 research outputs found

    Railway/Highway At-Grade Crossing Surface Management: An Overview

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    This report draws on data from around the United States to describe the features of a successful railway/highway at-grade crossing management program; it emphasizes the highway/trackbed structures and crossing surfaces. Developing a structurally adequate crossing system is imperative, as this will produce a smooth surface and a stable highway/trackbed that prolongs crossings’ lifespans while keeping maintenance costs low and minimizing the number of disruptions encountered by highway and railway traffic. An overview of the guidance issued by several transportation agencies and organizations to facilitate the design and construction of railway/highway at-grade crossings is included here. Equally important to developing a robust network of crossings is defining a clear division of labor between federal, state, and local transportation agencies and railroad companies. As such, this report discusses administrative procedures and state-level regulations that influence railway/highway at-grade crossing practices. This information is presented for AASHTO, AREMA, FRA, FHWA, MUTCD, as well as several states, including Illinois, Indiana, Iowa, Georgia, Michigan, and West Virginia

    Effect of Enhanced Trackbed Support on Railway/Highway At-Grade Crossing Performance

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    This report documents the long-term performance of 89 railway/highway at-grade crossings in Kentucky and adjacent states that contain asphalt underlayment underneath the ballast. Asphalt underlayment increases load carrying capacity for trains and highway vehicles while enhancing the support structure’s waterproofing and confinement. The asphalt underlayment crossings studied were installed at sites that had historically exhibited poor performance and short service lives. Most of the crossing sites evaluated were 10-15 years old; however, their ages ranged up to 30 years. All of the crossings investigated have shown excellent performance since the installation of asphalt underlayments. No crossing failures, such as excessive settlement or mud pumping, have been noted, and the service lives of the crossing surfaces have been significantly improved. Detailed results from periodic inspections are included. A literature survey focuses on eleven public agencies and railroad companies that implement asphalt underlayments. Most of these entities install asphalt underlayments at heavy traffic/tonnage crossings that have routinely shown evidence of weak support leading to inferior performance. This survey, along with the empirical results of this study, indicates that asphalt underlayment, irrespective of material used on crossing surfaces, extends the service life of crossings and improves their performance

    Railway/Highway At-Grade Crossing Surface Rehabilitation Manual: Recommendations and Guides

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    This Railway/Highway At-Grade Crossing Surface Rehabilitation Manual offers guidance to engineers and project planners for designing, constructing, and managing railway/highway crossing rehabilitation projects. The manual includes information on pre-project administration, project execution, and post-project management and oversight. Suggestions are provided for determining the most cost-effective rehabilitation procedure, techniques to insure the appropriate installation procedures are followed onsite, and instructions for post-project administration and inspection procedures. The primary goal of this manual is to aid with the implementation of a crossing rehabilitation program; all of its guidance underscores the importance of achieving costeffective solutions through the use of best practices to build crossings that are safe and smooth, perform at a high level, and have a long service life, which benefits railroads as well the driving public

    Recommendations for KYTC’s Railway/Highway At-Grade Crossing Surface Management Practices

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    An ideal Railway/Highway At-Grade Crossing Management program involves selecting costeffective practices when designing new crossings and rehabilitating existing crossings. This report outlines two strategies to enhance KYTC’s existing program. First, it describes a process that uses decision-option diagrams to optimize the assessment and implementation of engineering solutions in order to restore desired smoothness, minimize settlement in the postconstruction phase, and foster acceptable long-term performance of crossings following their rehabilitation. Decision-option diagrams rely on assessments that are site-specific and based on historical performance, the present observed performance and condition, and the measureable parameters specific to particular crossings. To supplement this process, the second strategy that this report proposes is the establishment of an effective managerial structure at KYTC that streamlines decision-making to ensure that the selected design is properly applied and implemented. Taken together, these proposals will significantly improve the state’s ability to systematically and cost-effectively repair deteriorated crossings

    Finishing the euchromatic sequence of the human genome

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    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∌99% of the euchromatic genome and is accurate to an error rate of ∌1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

    Harnessing the NEON data revolution to advance open environmental science with a diverse and data-capable community

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    It is a critical time to reflect on the National Ecological Observatory Network (NEON) science to date as well as envision what research can be done right now with NEON (and other) data and what training is needed to enable a diverse user community. NEON became fully operational in May 2019 and has pivoted from planning and construction to operation and maintenance. In this overview, the history of and foundational thinking around NEON are discussed. A framework of open science is described with a discussion of how NEON can be situated as part of a larger data constellation—across existing networks and different suites of ecological measurements and sensors. Next, a synthesis of early NEON science, based on >100 existing publications, funded proposal efforts, and emergent science at the very first NEON Science Summit (hosted by Earth Lab at the University of Colorado Boulder in October 2019) is provided. Key questions that the ecology community will address with NEON data in the next 10 yr are outlined, from understanding drivers of biodiversity across spatial and temporal scales to defining complex feedback mechanisms in human–environmental systems. Last, the essential elements needed to engage and support a diverse and inclusive NEON user community are highlighted: training resources and tools that are openly available, funding for broad community engagement initiatives, and a mechanism to share and advertise those opportunities. NEON users require both the skills to work with NEON data and the ecological or environmental science domain knowledge to understand and interpret them. This paper synthesizes early directions in the community’s use of NEON data, and opportunities for the next 10 yr of NEON operations in emergent science themes, open science best practices, education and training, and community building

    Rehabilitation, Assessment and Management Practices to Ensure Long-Life, High Performance Highway-Railway At-Grade Crossings

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    Rehabilitating and/or replacement of highway-railway at-grade crossings frequently accounts for major track maintenance expenses for the U.S. highway governmental agencies and the railroad industry. Substantial numbers of crossings deteriorate at a more rapid rate than the abutting trackbed and pavement. This is largely due to the structural implications of the combined highway and railway loadings within the jointly used crossing area and difficultly in maintaining adequate drainage within the immediate crossing area. A highway-railway at-grade crossing is designed to fulfill its primary purpose of providing a smooth surface for the safe passage of rubber-tired vehicles across the railroad. The jointly used area represents a significantly expensive unit cost of the highway and railway line. Ideally a highway crossing will maintain a smooth surface and stable trackbed for a long period of time. This reduces costly and frequent disruptions to highway and railway traffic when the track needs adjusting or the surface needs replacing due to rideability concerns. Technology is available for “fast-tracking” the renewal of highway crossings within one day (if desired) using a panel system with specifically designed layered support and premium materials. The procedure involves complete removal of the old crossing panel and trackbed materials. The replacement consists of an asphalt underlayment layer, a pre-compacted ballast layer, a new track panel, and a new crossing surface. The composition of the asphalt layer is similar to that used for highways. It replaces all, or a portion of, the typical granular subballast layer. A cooperative effort between the local highway agency and the railway company will ideally reduce costs, improve the quality of the finished product, and reduce outage of the highway and railroad during the rehabilitation process. A major objective is to minimize disruption to both highway and railway traffic during the renewal process in addition to improving the performance and extending the life of the crossing. Typical schedules are for the railroad to be out-of-service for a maximum of four hours and for the highway to be closed only eight to twelve hours, when length of closure is an issue of importance. Numerous long-term tests and performance evaluations of heavy trafficked railway and highway crossings are presented herein. Pressure cells have been imbedded within the trackbed to document pressure levels within the layered portion of the crossing structure due to loadings from trains and highway vehicles. In addition, long-term settlement measurements and assessments for several crossings are documented. The measurements indicate significantly reduced long-term settlements of crossings incorporating the rapid-renewal, layered system, while maintaining acceptable smoothness levels. In addition, standard practices and specifications are presented for several highway agencies and railway companies using this technology for their crossing renewal programs. These long-term performance evaluations indicate this practice ensures long-life, economical, smooth crossings for improved safety and operating performances. The application of this technology continues to increase and it is considered a standard practice in many areas of the country. A crossing management technique (model decision-making process) is described for assessing the optimum engineering solutions to restore desired smoothness, minimize subsequent settlement, and ensure acceptable long-term performances for highway-railway at-grade crossings. These are site-specific and based on historical performance, the present observed performance and condition, and measurable parameters for the particular crossing. The model decision-making process includes three options, depending on the source(s) of the crossing roughness. The process can involve merely making improvements to the quality of the pavement approaches. Another scenario can be to replace only the deteriorated crossing surface. The most involved solution is the complete renewal of the crossing surface, track panel, and underlying support to rectify a chronic problem that may be inhibiting the crossing from achieving optimum performance

    Study protocol for a hybrid type 1 effectiveness-implementation trial testing virtual tobacco treatment in oncology practices [Smokefree Support Study 2.0]

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    Abstract Background Persistent smoking among patients diagnosed with cancer is associated with adverse clinical outcomes, yet an evidence-based tobacco use intervention has not been well-integrated into cancer care in community oncology settings. This paper describes the protocol of a nation-wide clinical trial conducted by the ECOG-ACRIN National Cancer Institute (NCI) Community Oncology Research Program (NCORP) Research Base to assess the effectiveness of a virtual tobacco treatment intervention and the process of implementing tobacco treatment in NCORP community oncology settings. Methods/design This two-arm, multisite (n: 49 NCORP sites) hybrid type 1 effectiveness-implementation randomized controlled trial compares the effectiveness of a Virtual Intervention Treatment (VIT) versus an Enhanced Usual Control (EUC) among English and Spanish speaking patients recently diagnosed with cancer, reporting current smoking and receiving care at a participating NCORP Community or Minority/Underserved Site. The VIT includes up to 11 virtual counseling sessions with a tobacco treatment specialist and up to 12 weeks of nicotine replacement therapy (NRT). The EUC arm receives a referral to the NCI Quitline. The primary study outcome is biochemically confirmed 7-day point prevalence smoking abstinence. Moderators of treatment effect will be assessed. The study evaluates implementation processes from participating NCORP site staff via survey, administrative, and focus group data, including reach, acceptability, appropriateness, fidelity, feasibility, adoption, cost and sustainability outcomes. Discussion This trial will generate findings about the effectiveness of an evidence-based virtual tobacco treatment intervention targeting patients diagnosed with cancer and illuminate barriers and facilitators that influence implementing tobacco treatment into community oncology settings nationally. In the era of COVID-19, virtual care solutions are vital for maximizing access and utilization of tobacco treatment delivery. Trial registration ClinicalTrials.gov (NCT03808818) on January 18th, 2019; Last update posted: May 21st, 2020.http://deepblue.lib.umich.edu/bitstream/2027.42/173518/1/12889_2022_Article_13631.pd
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