Guidelines for Selecting Single-Point Urban and Diamond Interchanges: Nationwide Survey and Literature Review

Author(s):  
Michelle J. Smith ◽  
Nicholas J. Garber

Metropolitan areas in the United States are experiencing a steep increase in traffic growth and traffic congestion on their urban freeways. In the past, the most prevalent type of urban interchange has been the diamond interchange (DI). In more recent years, however, to overcome the need for significant additional right-of-way that is generally required for this type of interchange and still respond to increased traffic demand, a new type of interchange has emerged: the single-point urban interchange (SPUI). Traffic engineers do not agree about the relative operational efficiency of the SPUI compared with the DI. Also, the unfamiliar geometry and operation of the SPUI and its large, uncontrolled conflict area have raised several concerns about the safety of motorists who travel through it. The purpose of this study was to evaluate and compare the safety and operational characteristics of the SPUI and DI and to develop guidelines that identify traffic and geometric conditions that favor one over the other. We surveyed state traffic engineers across the nation about their experiences and opinions of the two interchanges in terms of operational performance and safety. A complete literature review on the subject revealed significant findings as well. We used both of these sources of information to develop guidelines to aid traffic engineers in selecting and designing the appropriate type of interchange.

2017 ◽  
Vol 2637 (1) ◽  
pp. 99-113 ◽  
Author(s):  
Zhixia Li ◽  
Madhav V. Chitturi ◽  
Andrea R. Bill ◽  
David A. Noyce

In the United States, roundabouts have recently been constructed to replace signalized intersections at freeway ramp terminals as both a safety and an operational treatment. In practice, this treatment is in need of guidelines specifying conditions when the roundabout or signalized intersection is more appropriate to assist practitioners in deciding which alternative to choose. In particular, research providing a comprehensive operational comparison between roundabouts and signalized interchanges is lacking. The current research—though a strictly calibrated microscopic simulation platform—analyzes and models the control delay at double-lane roundabouts and signalized interchanges. Both roundabouts and signalized interchanges were modeled in a Vissim simulation platform. Capacity at each roundabout entrance was calibrated and validated separately for passenger cars and heavy vehicles, since both vehicle types have different critical and follow-up headways. The design of the simulation experiments covered 2,880 different scenarios for roundabouts and signalized interchanges with varying ramp and arterial volumes, ramp spacing, and heavy-vehicle percentages. From the simulation results, control delay and level of service of the off-ramp and arterial approaches of roundabouts and signalized diamond interchanges were modeled and compared. Ultimately, guidelines for the selection between double-lane roundabouts and signalized interchanges were developed and presented in the form of look-up tables. These tables provide an easy-to-use tool for practitioners to determine the appropriate double-lane interchange to install under specific combinations of traffic demand, heavy-vehicle percentage, and ramp spacing conditions.


Author(s):  
Eon Kyo Shin ◽  
Jang Hee Lee ◽  
Ju Hyun Kim ◽  
Jung Sik Kim ◽  
Yong Woo Jeong

Severe traffic congestion often occurs at intersections of high-volume traffic arteries. To reduce this congestion, innovative intersection designs such as the single-point urban interchange (SPUI), center-turn overpass (CTO), and echelon interchange (EI) have been implemented. This paper introduces a new type of intersection, the two-level signalized intersection (TLSI), which improves the efficiency of intersection operations under a wide variety of traffic conditions. The paper compares the TLSI with other innovative intersection types. Unlike the SPUI, CTO, or EI, the TLSI provides for complete separation of east–west and north–south traffic. The TLSI also enables the use of directional separation and leading, lagging, or overlapping lefts on both upper and lower levels. Simulation results indicate that, compared with these other innovative intersection types, the TLSI has the shortest delay times in most evaluation scenarios as well as the least sensitivity to variations in traffic volume. However, the TLSI shows significant delay when traffic volumes on the major and minor roads are vastly different.


2020 ◽  
Vol 1 (2) ◽  
pp. 77-92
Author(s):  
Rotimi Williams Omotoye

Pentecostalism as a new wave of Christianity became more pronounced in 1970's and beyond in Nigeria. Since then scholars of Religion, History, Sociology and Political Science have shown keen interest in the study of the Churches known as Pentecostals because of the impact they have made on the society. The Redeemed Christian Church of God (RCCG) was established by Pastor Josiah Akindayomi in Lagos,Nigeria in 1952. After his demise, he was succeeded by Pastor Adeboye Adejare Enock. The problem of study of this research was an examination of the expansion of the Redeemed Christian Church of God to North America, Caribbean and Canada. The missionary activities of the church could be regarded as a reversed mission in the propagation of Christianity by Africans in the Diaspora. The methodology adopted was historical. The primary and secondary sources of information were also germane in the research. The findings of the research indicated that the Redeemed Christian Church of God was founded in North America by Immigrants from Nigeria. Pastor Adeboye Enock Adejare had much influence on the Church within and outside the country because of his charisma. The Church has become a place of refuge for many immigrants. They are also contributing to the economy of the United States of America. However, the members of the Church were faced with some challenges, such as security scrutiny by the security agencies. In conclusion, the RCCGNA was a denomination that had been accepted and embraced by Nigerians and African immigrants in the United States of America.


2021 ◽  
Vol 11 (3) ◽  
pp. 231
Author(s):  
Faven Butler ◽  
Ali Alghubayshi ◽  
Youssef Roman

Gout is an inflammatory condition caused by elevated serum urate (SU), a condition known as hyperuricemia (HU). Genetic variations, including single nucleotide polymorphisms (SNPs), can alter the function of urate transporters, leading to differential HU and gout prevalence across different populations. In the United States (U.S.), gout prevalence differentially affects certain racial groups. The objective of this proposed analysis is to compare the frequency of urate-related genetic risk alleles between Europeans (EUR) and the following major racial groups: Africans in Southwest U.S. (ASW), Han-Chinese (CHS), Japanese (JPT), and Mexican (MXL) from the 1000 Genomes Project. The Ensembl genome browser of the 1000 Genomes Project was used to conduct cross-population allele frequency comparisons of 11 SNPs across 11 genes, physiologically involved and significantly associated with SU levels and gout risk. Gene/SNP pairs included: ABCG2 (rs2231142), SLC2A9 (rs734553), SLC17A1 (rs1183201), SLC16A9 (rs1171614), GCKR (rs1260326), SLC22A11 (rs2078267), SLC22A12 (rs505802), INHBC (rs3741414), RREB1 (rs675209), PDZK1 (rs12129861), and NRXN2 (rs478607). Allele frequencies were compared to EUR using Chi-Square or Fisher’s Exact test, when appropriate. Bonferroni correction for multiple comparisons was used, with p < 0.0045 for statistical significance. Risk alleles were defined as the allele that is associated with baseline or higher HU and gout risks. The cumulative HU or gout risk allele index of the 11 SNPs was estimated for each population. The prevalence of HU and gout in U.S. and non-US populations was evaluated using published epidemiological data and literature review. Compared with EUR, the SNP frequencies of 7/11 in ASW, 9/11 in MXL, 9/11 JPT, and 11/11 CHS were significantly different. HU or gout risk allele indices were 5, 6, 9, and 11 in ASW, MXL, CHS, and JPT, respectively. Out of the 11 SNPs, the percentage of risk alleles in CHS and JPT was 100%. Compared to non-US populations, the prevalence of HU and gout appear to be higher in western world countries. Compared with EUR, CHS and JPT populations had the highest HU or gout risk allele frequencies, followed by MXL and ASW. These results suggest that individuals of Asian descent are at higher HU and gout risk, which may partly explain the nearly three-fold higher gout prevalence among Asians versus Caucasians in ambulatory care settings. Furthermore, gout remains a disease of developed countries with a marked global rising.


Sexes ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 331-344
Author(s):  
Jessamyn Bowling ◽  
Erika Montanaro ◽  
Sarai Guerrero-Ordonez ◽  
Stuti Joshi ◽  
Diana Gioia

In the United States, the COVID-19 pandemic has decreased partnered sexual behavior and increased the use of enhancement (e.g., toys). This has been partly attributed to reduced social interactions and stress. However, individuals’ perceptions of changes are missing in research. This study aims to examine how adults perceive changes in their sexuality during the pandemic. We conducted a nationwide survey of US adults from April–June 2020 (N = 326). This qualitative study examines the open-ended responses using thematic analyses. The following themes emerged from the data: (1) changes in the purpose of sex; (2) changes in sexual identity; (3) decreases in sex drive and desire; (4) increases in sex drive and desire; (5) fluctuations in sex drive and desire; (6) increased sexual experimentation and reflection. The stress, changes in home responsibilities and living situations, and time spent with partners (more or less) has affected individuals by increasing or decreasing their sex drive and desire. Participants responded to changes with self-reflection and awareness, and incorporating new practices (e.g., technology, kink). The purpose of sex has shifted in order to gain intimacy or connect, or to pass time. These changes were perceived as both positive and negative, and more research is needed to determine the durability of these changes.


Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4109
Author(s):  
Bożena Gajdzik ◽  
Radosław Wolniak

The publication presents a picture of modern steelworks that is evolving from steelworks 3.0 to steelworks 4.0. The paper was created on the basis of secondary sources of information (desk research). The entire publication concerns the emerging opportunities for the development of the steel producers to Industry 4.0 and the changes already implemented in the steel plants. The collected information shows the support environment for changes in the steel sector (EU programs), the levels of evolution of steel mills, along with the areas of change in the steel industry and implemented investment projects. The work consists of a theoretical part based on a literature review and a practical part based on case studies. The work ends with a discussion in which the staged and segmented nature of the changes introduced in the analyzed sector is emphasized. Based on the three case studies described in the paper, a comparative analysis was conducted between them. When we tried to compare methods used in the three analyzed steel producers (capital groups): ArcelorMittal, Thyssenkrupp, and Tata Steel Group, it can be seen that in all organizations, the main problem connected with steelworks 4.0 transition is the digitalization of all processes within an organization and in the entire supply chain. This is realized using various tools and methods but they are concentrated on using technologies and methods such as artificial intelligence, drones, virtual reality, full automatization, and industrial robots. The effects are connected to better relations with customers, which leads to an increase in customer satisfaction and the organizations’ profit. The steel industry will undergo further strong changes, bringing it closer to Industry 4.0 because it occupies an important place in the economies of many countries due to the strong dependence of steel producers on the markets of the recipients (steel consumers). Steel is the basic material needed to make many products, and its properties have been valued for centuries. In addition, steel mills with positive economic, social, and environmental aspects are part of the concept of sustainability for industries and economies.


2021 ◽  
pp. 1-41
Author(s):  
Ana Cristina Lindsay ◽  
Qun Le ◽  
Denise Lima Nogueira ◽  
Márcia M. T. Machado ◽  
Mary L. Greaney

Abstract Objectives: The objective of this study was to assess sources of information about gestational weight gain (GWG), diet, and exercise among first-time pregnant Brazilian women in the United States (US). Design: Cross-sectional survey. Setting: Massachusetts, United States. Participants: First-time pregnant Brazilian women. Results: Eighty-six women, the majority of whom were immigrants (96.5%) classified as having low-acculturation levels (68%), participated in the study. Approximately two-thirds of respondents had sought information about GWG (72.1%), diet (79.1%), and exercise (74.4%) via the internet. Women classified as having low acculturation levels were more likely to seek information about GWG via the internet (OR = 7.55; 95% CI: 1.41, 40.26) than those with high acculturation levels after adjusting for age and receiving information about GWG from healthcare provider (doctor or midwife). Moreover, many respondents reported seeking information about GWG (67%), diet (71%), and exercise (52%) from family and friends. Women who self-identified as being overweight pre-pregnancy were less likely to seek information about diet (OR = 0.32; 95% CI: 0.11, 0.93) and exercise (OR = 0.33; 95% CI: 0.11, 0.96) from family and friends than those who self-identified being normal weight pre-pregnancy. Conclusions: This is the first study to assess sources of information about GWG, diet, and exercise among pregnant Brazilian immigrants in the US. Findings have implications for the design of interventions and suggest the potential of mHealth intervention as low-cost, easy access option for delivering culturally and linguistically tailored evidence-based information about GWG incorporating behavioral change practices to this growing immigrant group.


2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S400-S400
Author(s):  
Thomas D Dieringer ◽  
Glen Huang ◽  
Paul R Allyn ◽  
Jeffrey Klausner

Abstract Background Homelessness has been a growing issue in the United States and worldwide. Bartonella quintana, the causative agent of “Trench fever”, is a well known illness among homeless populations in urban centers. While many cases of B. quintana are self limited, the disease can have advanced presentations including endocarditis. We present a short case series of three cases of B. quintana infective endocarditis (IE) in homeless individuals in Los Angeles and review the literature of cases of B. quintana IE in the homeless population. Methods Here we report three cases of B. quintana IE encountered in homeless individuals at the University of California, Los Angeles (UCLA) hospital system. A literature review was also conducted. PubMed was searched for published cases of human IE secondary to B. quintana in homeless individuals. Results All three patients were male with ages ranging from 39 to 57 years old with a history of homelessness and alcohol use. Presentations were subacute to chronic in nature consisting of constitutional symptoms as well as a range of symptoms corresponding with heart and renal failure. Each patient was found to have varying degrees of aortic insufficiency with either identified aortic valve vegetation or valvular thickening. Diagnosis was made with a combination of Bartonella serologies and whole genome sequencing PCR. All three patient’s courses were complicated by renal failure at varying points limiting the use of gentamicin for the full treatment course. Two patients ultimately underwent aortic valve replacement due to severe aortic insufficiency and completed therapy with doxycycline and rifampin. A single patient was discharged with plan to complete doxycycline and rifampin therapy however was lost to follow up. A literature review of 10 manuscripts describing 13 cases of B. quintana IE were identified. All the patients were male and the median age was 45. Six of the cases were in Europe and eight were in North America. All cases had left sided valve involvement (10 aortic, 6 mitral, 3 both valves). No cases of right sided IE were identified. Conclusion B. quintana IE should be considered in homeless patients with a clinical presentation concerning for IE. A combination of serology and PCR testing can be useful in diagnosis of this uncommon cause of infective endocarditis. Disclosures Jeffrey Klausner, MD, MPH, Nothing to disclose


2020 ◽  
pp. 1-4
Author(s):  
Madhusudan Ganigara ◽  
Chetan Sharma ◽  
Fernando Molina Berganza ◽  
Krittika Joshi ◽  
Andrew D. Blaufox ◽  
...  

Abstract The coronavirus disease 2019 (COVID-19) pandemic has had a profound impact on medical educational curricula. We aimed to examine the impact of these unprecedented changes on the formal education of paediatric cardiology fellows through a nationwide survey. A REDCap™-based voluntary anonymous survey was sent to all current paediatric cardiology fellows in the United States of America in May, 2020. Of 143 respondents, 121 were categorical fellows, representing over one-fourth of all categorical paediatric cardiology fellows in the United States of America. Nearly all (140/143, 97.9%) respondents utilised online learning during the pandemic, with 134 (93.7%) reporting an increase in use compared to pre-pandemic. The percentage of respondents reporting curriculum supplementation with outside lectures increased from 11.9 to 88.8% during the pandemic. Respondents considered online learning to be “equally or more effective” than in-person lectures in convenience (133/142, 93.7%), improving fellow attendance (132/142, 93.0%), improving non-fellow attendance (126/143, 88.1%), and meeting individual learning needs (101/143, 70.6%). The pandemic positively affected the lecture curriculum of 83 respondents (58.0%), with 35 (24.5%) reporting no change and 25 (17.5%) reporting a negative effect. A positive effect was most noted by those whose programmes utilised supplemental outside lectures (62.2 versus 25.0%, p = 0.004) and those whose lecture frequency did not decrease (65.1 versus 5.9%, p < 0.001). Restrictions imposed by the COVID-19 pandemic have greatly increased utilisation of online learning platforms by medical training programmes. This survey reveals that an online lecture curriculum, despite inherent obstacles, offers advantages that may mitigate some negative consequences of the pandemic on fellowship education.


2021 ◽  
pp. 003335492110181
Author(s):  
Richard J. Martino ◽  
Kristen D. Krause ◽  
Marybec Griffin ◽  
Caleb LoSchiavo ◽  
Camilla Comer-Carruthers ◽  
...  

Objectives Lesbian, gay, bisexual, transgender, or queer and questioning (LGBTQ+) people and populations face myriad health disparities that are likely to be evident during the COVID-19 pandemic. The objectives of our study were to describe patterns of COVID-19 testing among LGBTQ+ people and to differentiate rates of COVID-19 testing and test results by sociodemographic characteristics. Methods Participants residing in the United States and US territories (N = 1090) aged ≥18 completed an internet-based survey from May through July 2020 that assessed COVID-19 testing and test results and sociodemographic characteristics, including sexual orientation and gender identity (SOGI). We analyzed data on receipt and results of polymerase chain reaction (PCR) and antibody testing for SARS-CoV-2 and symptoms of COVID-19 in relation to sociodemographic characteristics. Results Of the 1090 participants, 182 (16.7%) received a PCR test; of these, 16 (8.8%) had a positive test result. Of the 124 (11.4%) who received an antibody test, 45 (36.3%) had antibodies. Rates of PCR testing were higher among participants who were non–US-born (25.4%) versus US-born (16.3%) and employed full-time or part-time (18.5%) versus unemployed (10.8%). Antibody testing rates were higher among gay cisgender men (17.2%) versus other SOGI groups, non–US-born (25.4%) versus US-born participants, employed (12.6%) versus unemployed participants, and participants residing in the Northeast (20.0%) versus other regions. Among SOGI groups with sufficient cell sizes (n > 10), positive PCR results were highest among cisgender gay men (16.1%). Conclusions The differential patterns of testing and positivity, particularly among gay men in our sample, confirm the need to create COVID-19 public health messaging and programming that attend to the LGBTQ+ population.


Sign in / Sign up

Export Citation Format

Share Document