313 research outputs found

    Characterizing Interstate Crash Rates Based on Traffic Congestion Using Probe Vehicle Data

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    Crash reduction factors are widely used by engineers for prioritizing safety investments. Work zones are routinely analyzed by the length and duration of queues. Queue detection warning technology has been growing in availability and reliability in recent years. However, there is sparse literature on the impact of freeway queueing on crash rates. This paper analyzes three years of crash data and crowdsourced probe vehicle data to classify crashes as being associated with queueing conditions or free flow conditions. In 2014, only 1.2% of the distanced-weighted hours of operation of Indiana interstates operated at or under 45 MPH. A three-year study on Indiana interstates indicates that commercial vehicles were involved in over 87% of back-of-queue fatal crashes compared to 39% of all fatal crashes during free flow conditions. A new measure of crash rate was developed to account for the presence and duration of queues: crashes per mile-hour of congestion. The congested crash rate on all Indiana interstates in 2014 was found to be 24 times greater than the uncongested crash rate. These data were also separated into both rural and urban categories. In rural areas, the congested crash rate is 23 times the uncongested crash rate. In urban areas, the congested crash rate is 21 times the uncongested crash rate. Queues are found to be present for five minutes or longer prior to approximately 90% of congestion crashes in 2014. Longer term, this information shows the importance in the development of technology that can warn motorists of traffic queues

    Characterizing Interstate Crash Rates Based on Traffic Congestion Using Probe Vehicle Data

    Get PDF
    Crash reduction factors are widely used by engineers for prioritizing safety investments. Work zones are routinely analyzed by the length and duration of queues. Queue detection warning technology has been growing in availability and reliability in recent years. However, there is sparse literature on the impact of freeway queueing on crash rates. This paper analyzes three years of crash data and crowd-sourced probe vehicle data to classify crashes as being associated with queueing conditions or free flow conditions. In 2014, only 1.2% of the distanced-weighted hours of operation of Indiana interstates operated at or under 45 MPH. A three-year study on Indiana interstates indicates that commercial vehicles were involved in over 87% of back-of-queue fatal crashes compared to 39% of all fatal crashes during free flow conditions. A new measure of crash rate was developed to account for the presence and duration of queues: crashes per mile-hour of congestion. The congested crash rate on all Indiana interstates in 2014 was found to be 24 times greater than the uncongested crash rate. These data were also separated into both rural and urban categories. In rural areas, the congested crash rate is 23 times the uncongested crash rate. In urban areas, the congested crash rate is 21 times the uncongested crash rate. Queues are found to be present for five minutes or longer prior to approximately 90% of congestion crashes in 2014. Longer term, this information shows the importance in the development of technology that can warn motorists of traffic queues

    Performance Ranking of Arterial Corridors Using Travel Time and Travel Time Reliability Metrics

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    Performance measures are important for managing transportation systems and demonstrating accountability. This session presents a scalable methodology for analyzing arterial travel times, taking into account both the central tendency of the travel time and its reliability. Findings will be presented from a pilot analysis that was carried out for 28 arterials including a total of 341 signalized intersections from across the state of Indiana

    Real-Time Probe Data Dashboard for Monitoring Detour Route during I-65 N Road Closure

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    On August 7, 2015, a 37 mile stretch of I-65 N from MM 141 to 178 was closed due to a structural evaluation of a bridge. Traffic was detoured onto US-52, SR-26, and US-231 before returning to the highway. In order to monitor delay and congestion on the detour route, a real-time dashboard was implemented in the style of the interstate Traffic Ticker. Throughout the detour, this website was used to monitor congestion in real time and measure the impact of mitigation actions. The improvement in travel can be seen from the addition of temporary signals, retiming of the US-231 corridor, and conversion of US-231 and SR-18 to a two-way stop

    Inelastic collapse of a randomly forced particle

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    We consider a randomly forced particle moving in a finite region, which rebounds inelastically with coefficient of restitution r on collision with the boundaries. We show that there is a transition at a critical value of r, r_c\equiv e^{-\pi/\sqrt{3}}, above which the dynamics is ergodic but beneath which the particle undergoes inelastic collapse, coming to rest after an infinite number of collisions in a finite time. The value of r_c is argued to be independent of the size of the region or the presence of a viscous damping term in the equation of motion.Comment: 4 pages, REVTEX, 2 EPS figures, uses multicol.sty and epsf.st

    Identifying Effects and Applications of Fixed and Variable Speed Limits

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    In Indiana, distracted driving and unexpected queues have led to an increase in the amount of back-of-queue crashes, particularly on approach to work zones. This report presents new strategies for the assessment of both transportation safety and traffic operations using crowd-sourced probe vehicle data and a speed laser vehicle re-identification scheme. This report concludes by recommending strategies for the placement of variable speed limits (VSL) adjacent to work zones and suggestions for future research

    Respiratory Syncytial Virus Binds and Undergoes Transcription in Neutrophils From the Blood and Airways of Infants With Severe Bronchiolitis

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    Background. Neutrophils are the predominant cell in the lung inflammatory infiltrate of infants with respiratory syncytial virus (RSV) bronchiolitis. Although it has previously been shown that neutrophils from both blood and bronchoalveolar lavage (BAL) are activated, little is understood about their role in response to RSV infection. This study investigated whether RSV proteins and mRNA are present in neutrophils from blood and BAL of infected infants

    p107 regulates neural precursor cells in the mammalian brain

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    Here we show a novel function for Retinoblastoma family member, p107 in controlling stem cell expansion in the mammalian brain. Adult p107-null mice had elevated numbers of proliferating progenitor cells in their lateral ventricles. In vitro neurosphere assays revealed striking increases in the number of neurosphere forming cells from p107−/− brains that exhibited enhanced capacity for self-renewal. An expanded stem cell population in p107-deficient mice was shown in vivo by (a) increased numbers of slowly cycling cells in the lateral ventricles; and (b) accelerated rates of neural precursor repopulation after progenitor ablation. Notch1 was up-regulated in p107−/− neurospheres in vitro and brains in vivo. Chromatin immunoprecipitation and p107 overexpression suggest that p107 may modulate the Notch1 pathway. These results demonstrate a novel function for p107 that is distinct from Rb, which is to negatively regulate the number of neural stem cells in the developing and adult brain

    Neurology and the histiocytoses: a case of Rosai-Dorfman-Destombes disease

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    The histiocytoses are a group of rare disorders characterised by the accumulation of neoplastic or non-neoplastic activated histiocytes in various tissues. Phenotypes vary widely from cutaneous lesions or lymphadenopathy that regress spontaneously to disseminated disease with poor prognosis. Neurological symptoms can be a presenting feature or appear during the course of disease. We present a challenging diagnostic and management case of Rosai-Dorfman-Destombes disease in a 48-year-old woman with a relapsing, partially steroid-responsive syndrome comprising patchy, non-length-dependent radiculoneuropathy with diffuse pachymeningitis and widespread systemic disease, and recent dramatic response to novel mitogen-activated kinase pathway inhibition. We discuss the clinical characteristics, diagnosis, recent breakthroughs in pathogenesis and emerging treatment options for Rosai-Dorfman disease and for the histiocytoses with neurological sequelae, including Langerhans cell histiocytosis and Erdheim-Chester disease

    One Health: Addressing the Challenges of Global Health and Food Security panel

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    This panel will provided an expert-centered overview of operational, policy, and critical decision-making threats, opportunities, and strengths that shape the effectiveness of health and food protection and security locally, nationally, and transnationally. Perspectives addressed proactive, trans-operational, commercializable, and innovative R&D approaches to these objectives. WARNING: The presentation by Dr. Stephen Barnes entitled "Lessons learned from combat casualty care" contains graphic images of wounds sustained in combat. Viewer discretion is strongly advised
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