Safety Impacts of Access Management Features near Roundabouts

Author(s):  
Priyanka Alluri ◽  
Albert Gan ◽  
Andres Diaz ◽  
Ruth Steiner

Roundabouts can better facilitate U-turns and provide better safety, especially in reducing severe crashes, than can traditional intersections. Roundabouts, instead of traditional signalized intersections, increasingly are being installed on busy arterial streets. Even though roundabouts gradually are becoming integral to regional transportation networks, no literature addresses the safety impacts of access management features such as driveways and median openings along corridors with roundabouts. The existing access management guidelines for signalized intersections are not directly applicable to roundabouts because traffic operations are different at the two types of intersections. In this study the safety impact of access features near roundabouts was investigated. In particular, three potential safety concerns associated with roundabouts were studied in commercial areas in Florida: (a) the impact of driveway corner clearances on roundabout safety, (b) the safety impact of median openings near roundabouts, and (c) the safety at roundabouts that provided direct access to activity centers. Data for the analysis reflected 131 roundabouts in commercial areas in Florida. Police reports for more than 1,000 crashes that occurred in roundabout influence areas between 2007 and 2011 were reviewed carefully to identify crash patterns and causes related to specific roundabout designs, con-figurations, and access features. Recommendations are made for access features near roundabouts in commercial areas.

Author(s):  
Yi Zhao ◽  
Rachel M. James ◽  
Lin Xiao ◽  
Joe Bared

Alternative intersection designs are increasingly proposed and adopted by different agencies to meet the needs of growing traffic demand and constrained transportation resources. The left turn (LT) is one of the most critical movements at signalized intersections from both a safety and operations perspective. Heavy LT volumes are especially impactful to the operational efficiency of a signalized intersection and often result in queue spillback. A contraflow left-turn pocket lane (CLPL) is proposed to mitigate congestion caused by heavy LT demand and has been shown in simulation to greatly mitigate the impact of queue spillback. The CLPL dynamically uses the opposing through lane (OTL) as an additional LT lane within the signal cycle on a temporary basis when the OTL is not occupied by through traffic. While geometric design schematics and analytical procedures for estimating delay have been proposed and discussed in existing literature, methodologies for estimating capacity benefits and traffic operations are not yet well defined. This paper has three primary contributions to the literature: development of a probabilistic capacity estimation model, exploration of the impact of key characteristics (e.g., cycle length, LT demand, lane selection preference) on estimated intersection capacity, and recommendations for the real-world implementation of a CLPL. The simulation results indicate that the CLPL treatment can increase a signalized intersection’s throughput up to 25% and decrease the intersection’s average delay by 35%.


BMJ Open ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. e039488
Author(s):  
Anna Dowling ◽  
Ellen Slungaard ◽  
Nicola R Heneghan

IntroductionThe prevalence of flight-related neck pain is 70% in UK fast jet pilots; much higher than the general population. The Aircrew Conditioning Programme and direct access physiotherapy exist to minimise the impact on military capability, but a population specific patient-reported outcome measure (PROM) is required to investigate the effectiveness of these. We aimed to explore the experiences of flight-related neck pain to inform the content validity and development of a population specific PROM.MethodsQualitative semistructured interviews combining phenomenological and grounded theory methods, reported using Consolidated criteria for Reporting Qualitative research guidelines. A purposive sample of 10 fast jet pilots with neck pain was recruited. Concept elicitation interviews were audio recorded, transcribed verbatim along with field notes. Data analysis involved subject and methodological expertise used a concept elicitation approach.ResultsParticipants included 10 male fast jet pilots, age 34.7 years. Identified themes included: (1) physical symptoms associated with flying activities; (2) occupational effects revealed modifications of flying, or ‘suboptimal’ performance owing to neck pain; (3) psychological effects revealed feelings or worry and (4) social and activity effects showed impact on out of work time.ConclusionPopulation-specific occupational, psychological and social factors should be considered alongside physical symptoms when managing neck pain in military aircrew. Findings support the development of a PROM specifically designed for military aircrew with neck pain.


2021 ◽  
Vol 11 (8) ◽  
pp. 3580
Author(s):  
Cristina Val-Peón ◽  
Juan I. Santisteban ◽  
José A. López-Sáez ◽  
Gerd-Christian Weniger ◽  
Klaus Reicherter

The SW coast of the Iberian Peninsula experiences a lack of palaeoenvironmental and archaeological data. With the aim to fill this gap, we contribute with a new palynological and geochemical dataset obtained from a sediment core drilled in the continental shelf of the Algarve coast. Archaeological data have been correlated with our multi-proxy dataset to understand how human groups adapted to environmental changes during the Early-Mid Holocene, with special focus on the Mesolithic to Neolithic transition. Vegetation trends indicate warm conditions at the onset of the Holocene followed by increased moisture and forest development ca. 10–7 ka BP, after which woodlands are progressively replaced by heaths. Peaks of aridity were identified at 8.2 and 7. 5 ka BP. Compositional, textural, redox state, and weathering of source area geochemical proxies indicates abrupt palaeoceanographic modifications and gradual terrestrial changes at 8.2 ka BP, while the 7.5 ka BP event mirrors a decrease in land moisture availability. Mesolithic sites are mainly composed of seasonal camps with direct access to the coast for the exploitation of local resources. This pattern extends into the Early Neolithic, when these sites coexist with seasonal and permanent occupations located in inland areas near rivers. Changes in settlement patterns and dietary habits may be influenced by changes in coastal environments caused by the sea-level rise and the impact of the 8.2 and 7.5 ka BP climate events.


2021 ◽  
Vol 47 (1) ◽  
Author(s):  
M. Marano ◽  
F. Rossi ◽  
L. Ravà ◽  
M. Khalil Ramla ◽  
M. Pisani ◽  
...  

Abstract Introduction Acute pediatric poisoning is an emerging health and social problem. The aim of this study is to describe the characteristics of a large pediatric cohort exposed to xenobiotics, through the analysis of a Pediatric Poison Control Center (PPCc) registry. Methods This study, conducted in the Pediatric Hospital Bambino Gesù of Rome, a reference National Pediatric Hospital, collected data of children whose parents or caregivers contacted the PPCc by phone (group “P”), or who presented to the Emergency Department (group “ED”), during the three-year period 2014–2016. Data were prospectively and systematically collected in a pre-set electronic registry. Comparisons among age groups were performed and multivariable logistic regression models used to investigate associations with outcomes (hospital referral for “P”, and hospital admission for “ED”group). Results We collected data of 1611 children on group P and 1075 on group ED. Both groups were exposed to both pharmaceutical and non-pharmaceutical agents. Pharmaceutical agent exposure increased with age and the most common route of exposure was oral. Only 10% among P group were symptomatic children, with gastrointestinal symptoms. Among the ED patients, 30% were symptomatic children mostly with gastrointestinal (55.4%) and neurologic symptoms (23.8%). Intentional exposure (abuse substance and suicide attempt), which involved 7.7% of patients, was associated with older age and Hospital admission. Conclusions Our study describes the characteristics of xenobiotics exposures in different paediatric age groups, highlighting the impact of both pharmacological and intentional exposure. Furthermore, our study shows the utility of a specific PPCc, either through Phone support or by direct access to ED. PPCc phone counselling could avoid unnecessary access to the ED, a relevant achievement, particularly in the time of a pandemic.


2021 ◽  
Vol 108 (Supplement_2) ◽  
Author(s):  
M Asarbakhsh ◽  
N Lazarus ◽  
P Lykoudis

Abstract Background The definitive management of acute cholecystitis is laparoscopic cholecystectomy on the same admission if the patient is fit. As the Covid-19 pandemic emerged, evidence suggested adverse outcomes for asymptomatic Covid positive patients undergoing surgery, including increased mortality risk. Risks to theatre staff were also highlighted. This prompted changes in acute cholecystitis management guidelines. Method The audit aim was to assess the impact of guideline change on clinical outcomes and readmission rate for acute cholecystitis. The revised Association of Upper Gastrointestinal Surgeons of Great Britain and Ireland (AUGIS) guidelines were the gold standard. All inpatient admissions for acute cholecystitis during the 4-week peak of the pandemic (17/04/2020 – 14/05/2020) were included. Result 24 patients were admitted with acute cholecystitis. 10 patients (41.7%) were managed with antibiotics alone, 4 patients (16.6%) underwent cholecystostomy. 12 patients (50%) were discharged within 3 days. Lack of clinical progress/ongoing symptoms was the indication for laparoscopic cholecystectomy in 5 cases (20.8%). 5 conservatively managed patients (20.8%) were readmitted with ongoing cholecystitis or pancreatitis. Conclusions 19 patients (80%) were managed non-surgically in accordance with AUGIS guidelines. However conservative management was not always appropriate. We recommend that laparoscopic cholecystectomy should remain a management option for acute cholecystitis during the ongoing Covid-19 pandemic.


2015 ◽  
Vol 1762 ◽  
Author(s):  
Jeno Balogh ◽  
Sandra Haynes ◽  
Aaron Brown

ABSTRACTThis paper presents the impact of three undergraduate research projects focusing on constructability assessment of adhesive-based wood-concrete composite structural members, on a solar heating technology that can be utilized in conjunction with this system and how these projects relate to engineering education and program development at Metropolitan State University of Denver (MSU Denver). The sustainable structures topic was pursued within senior project classes offered in summer 2013 and 2014 at MSU Denver. The first project addressed new members, while the second dealt with retrofits. These projects were motivated by faculty research in developing new sustainable construction systems using composites. Since underlining faculty research is on an international scale, students had direct access to researchers world-wide. Such research was used as an instrument in the “Experimental Methods in Structural Engineering” course. The students were also exposed to a broader-range of diverse ideas within the field of research by attending an international conference on timber bridges. The solar furnace project was run in parallel, providing students an opportunity to conduct research targeted at design and performance optimization of the heating units with the intention to assess the benefits of incorporating these devices into future buildings using the sustainable structural system technology. Experiences gained through the undergraduate research activities were applied in the design of a proposed Sustainable Systems Engineering degree program.


2013 ◽  
Vol 805-806 ◽  
pp. 334-337
Author(s):  
Shi Wei Su ◽  
You Wei Zhou ◽  
Wei Xiong

Analysis compares the direct access to a single set of wind power systemTwo groups of wind farm access system directlyMultiple sets of wind farm access system directly And Multiple sets of wind dispersion access system's impact on power system transient stability. And compare the simulation results, Concluded that wind farm access capacity and its topology structure's influence on system transient stability.


Author(s):  
Michelle M. Mekker ◽  
Yun-Jou Lin ◽  
Magdy K. I. Elbahnasawy ◽  
Tamer S. A. Shamseldin ◽  
Howell Li ◽  
...  

Extensive literature exists regarding recommendations for lane widths, merging tapers, and work zone geometry to provide safe and efficient traffic operations. However, it is often infeasible or unsafe for inspectors to check these geometric features in a freeway work zone. This paper discusses the integration of LiDAR (Light Detection And Ranging)-generated geometric data with connected vehicle speed data to evaluate the impact of work zone geometry on traffic operations. Connected vehicle speed data can be used at both a system-wide (statewide) or segment-level view to identify periods of congestion and queueing. Examples of regional trends, localized incidents, and recurring bottlenecks are shown in the data in this paper. A LiDAR-mounted vehicle was deployed to a variety of work zones where recurring bottlenecks were identified to collect geometric data. In total, 350 directional miles were covered, resulting in approximately 360 GB of data. Two case studies, where geometric anomalies were identified, are discussed in this paper: a short segment with a narrow lane width of 10–10.5 feet and a merging taper that was about 200 feet shorter than recommended by the Manual on Uniform Traffic Control Devices. In both case studies, these work zone features did not conform to project specifications but were difficult to assess safely by an inspector in the field because of the high volume of traffic. The paper concludes by recommending the use of connected vehicle data to systematically identify work zones with recurring congestion and the use of LiDAR to assess work zone geometrics.


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