scholarly journals PEDESTRIAN LEVEL OF SERVICE: THE IMPACT OF SOCIAL GROUPS ON PEDESTRIAN FLOW CHARACTERISTICS

2016 ◽  
pp. 479-488
Author(s):  
ELVEZIA M. CEPOLINA ◽  
FEDERICO MENICHINI ◽  
PALOMA GONZALEZ ROJAS
Keyword(s):  
Social Groups ◽  
Flow Characteristics ◽  
Level Of Service ◽  
Pedestrian Flow ◽  
Pedestrian Level Of Service ◽  
The Impact

Effect of On-Street Parking on Pedestrian Flow Characteristics and Level of Service - An Indian Viewpoint

2021 ◽  
Author(s):  
Ninad Gore ◽  
Sanjay Dave ◽  
Jiten Shah ◽  
Shriniwas Arkatkar ◽  
Srinivas Pulugurtha
Keyword(s):  
Flow Characteristics ◽  
Level Of Service ◽  
Pedestrian Flow

What Are the Most Important Factors for Pedestrian Level-of-Service Estimation? A Systematic Review of the Literature

2018 ◽  
Vol 2672 (35) ◽  
pp. 101-117 ◽  
Author(s):  
Nowar Raad ◽  
Matthew I. Burke
Keyword(s):  
Systematic Review ◽  
Literature Review ◽  
Motor Vehicle ◽  
Level Of Service ◽  
Pedestrian Flow ◽  
Review Of The Literature ◽  
Rater Reliability ◽  
Pedestrian Level Of Service

Pedestrian environments are becoming more important in an urbanizing world where walking is increasingly being encouraged. Engineers and planners determine a link’s performance using measures codified as level-of-service, which provide guidance on acceptable or desirable standards. A range of approaches are used in determining pedestrian level-of-service (PLOS), incorporating a wide variety of factors and with much debate as to what should or should not be used. There has been no systematic attempt to synthesize this research and provide an over-arching perspective. Our review surveyed PLOS models from the peer-reviewed literature using a systematic quantitative literature review method based on the protocol developed by the Preferred Reporting Items for Systematic Review Recommendations (PRISMA). PLOS models are increasingly being developed; 22 of the 58 studies surveyed were produced since 2013. Earlier work adapted approaches used to determine automobile LOS to PLOS. Later approaches use a much wider range of factors but with very little consistency across the studies surveyed. Collectively these factors can be grouped in themes of: comfort, safety, and mobility. The most used factors were, in order: footpath width; obstructions to pedestrian flow; motor vehicle speeds and volumes; shoulder widths; and buffers such as on-street parking. However, many of the factors being included have not been empirically studied and almost none of the tools in use have been tested for such matters as inter-rater reliability.

scholarly journals Pedestrian Flow Characteristics at Upstream and Downstream of Bottleneck for Unidirectional Flow under Normal Conditions

2020 ◽  
Vol 5 ◽  
Author(s):  
Siddhartha Gulhare ◽  
Aparna P M ◽  
Ashish Verma
Keyword(s):  
Local Density ◽  
Flow Behavior ◽  
Flow Characteristics ◽  
General Assumption ◽  
Flow Speed ◽  
Real Field ◽  
Level Of Service ◽  
Pedestrian Flow ◽  
Pedestrian Movement ◽  
Density Values

The study of pedestrian flow characteristics at upstream and downstream of bottlenecks is important from level of service and evacuation perspective. Many controlled laboratory experiments have been conducted to study pedestrians’ behavior at bottlenecks. However, it is unclear whether experiments can reproduce real crowd flow characteristics. In this paper, real field data was collected at normal conditions for unidirectional pedestrian movement at Mahakaleshwar, a Hindu temple at Ujjain, India during Mahashivaratri, a festival day on which a large number of pilgrims visited the temple. Along the corridor there is a width reduction at a U-turn which creates a bottleneck. It is necessary to study pedestrian flow characteristics at bottlenecks to ensure desired level of service at temple premises during heavy flow. The speed-density relationships of upstream and downstream sections were compared and it was found that flow behavior at both the sections of bottleneck severely differ from each other. Pedestrians in the upstream are either at free flow speed for very low density values or moving slowly for intermediate to high range of density values. From the speed-density relationship, it can be concluded that pedestrians at upstream had visual clues of congestion ahead at bottleneck (pedestrian could also see the downstream flow through barricades). Therefore, pedestrians wait at their position, stay in their comfort zone and do not push each other. Thus, even at intermediate local density, pedestrians have such low speeds. This violates the general assumption that pedestrians change their speed only at the shockwave boundary. The movement of pedestrians at upstream is governed by local density and information of congestion status ahead, whereas pedestrian movement at downstream is governed by factors like density, side friction and pedestrians’ willingness to compensate for the delay at bottleneck. This study is expected to have application in planning and operation of pedestrian facilities.

scholarly journals Pedestrian flow characteristics and level of service on dissimilar facilities: A critical review

2018 ◽  
Vol 3 ◽  
Author(s):  
Arunabha Banerjee ◽  
Akhilesh Kumar Maurya ◽  
Gregor Lämmel
Keyword(s):  
Traffic Control ◽  
Flow Characteristics ◽  
Level Of Service ◽  
Pedestrian Flow ◽  
Asian Countries ◽  
Qualitative Survey ◽  
Directional Movement ◽  
Highly Correlated ◽  
Major Factors ◽  
Walking Speeds

Flow characteristics and Level of Service (LOS) are two terms which are highly correlated, where the flow characteristics of a particular pedestrian or a group of pedestrians over a facility greatly influence the level of service of that facility. This paper does an exhaustive review of the flow characteristics and level of service and how different factors are observed to influence the movement over different types of pedestrian facilities. Previous attempts have been made by different researchers to explore pedestrian flow characteristics and level of service, but such attempts were done separately and not in a combined manner. As mentioned above it is extremely important to study both flow characteristics and level of service together as it allows for a better understanding of the facility. The review highly focusses on the studies which were conducted facility wise using either qualitatively or quantitatively techniques in Western as well as Asian countries. It was observed that researchers mostly used single regime approach to capture uni- and bi-directional movement to develop fundamental relationships. Age, gender, width, attire, gradient and group size were some of the major factors that were observed to affect average walking speeds. To develop LOS, videography technique was more preferred in the western countries while questionnaire survey was more used in the Asian countries. For the qualitative survey, safety, comfort, accessibility and traffic control were common parameters chosen, while space, flow and delay were mostly used to define quantitative measures. Critical assessments are made, and research gaps are identified as well. The study shows that it is of utmost importance that both flow characteristics and level of service are studied together as it allows a better understanding of the current existing scenario as well as it captures the actual pedestrian movements over that particular pedestrian facility. Moreover, recommendations are also made which might be of utmost relevance to future researchers who might want to use the substance of this paper in order to arrive at different decisions on how to conduct data collection and analyse such data accordingly under different conditions and over different facilities.

scholarly journals Frame me if you must: PrEP framing and the impact on adherence to HIV Pre-exposure Prophylaxis

2017 ◽  
Vol 4 (suppl_1) ◽  
pp. S439-S439
Author(s):  
Eric Ellorin ◽  
Jill Blumenthal ◽  
Sonia Jain ◽  
Xiaoying Sun ◽  
Katya Corado ◽  
...  
Keyword(s):  
A Priori ◽  
Social Groups ◽  
Continuous Measure ◽  
Gay Community ◽  
Randomized Controlled ◽  
Exposure Prophylaxis ◽  
The Impact ◽  
Actual Prevalence ◽  
Tenofovir Diphosphate

Abstract Background “PrEP whore” has been used both as a pejorative by PrEP opponents in the gay community and, reactively, by PrEP advocates as a method to reclaim the label from stigmatization and “slut-shaming.” The actual prevalence and impact of such PrEP-directed stigma on adherence have been insufficiently studied. Methods CCTG 595 was a randomized controlled PrEP demonstration project in 398 HIV-uninfected MSM and transwomen. Intracellular tenofovir-diphosphate (TFV-DP) levels at weeks 12 and 48 were used as a continuous measure of adherence. At study visits, participants were asked to describe how they perceived others’ reactions to them being on PrEP. These perceptions were categorized a priori as either “positively framed,” “negatively framed,” or both. We used Wilcoxon rank-sum to determine the association between positive and negative framing and TFV-DP levels at weeks 12 and 48. Results By week 4, 29% of participants reported perceiving positive reactions from members of their social groups, 5% negative, and 6% both. Reporting decreased over 48 weeks, but positive reactions were consistently reported more than negative. At week 12, no differences in mean TFV-DP levels were observed in participants with positively-framed reactions compared with those reporting no outcome or only negatively-framed (1338 [IQR, 1036-1609] vs. 1281 [946-1489] fmol/punch, P = 0.17). Additionally, no differences were observed in those with negative reactions vs. those without (1209 [977–1427] vs. 1303 [964–1545], P = 0.58). At week 48, mean TFV-DP levels trended toward being higher among those that report any reaction, regardless if positive (1335 [909–1665] vs. 1179 [841–1455], P = 0.09) or negative (1377 [1054–1603] vs. 1192 [838–1486], P = 0.10) than those reporting no reaction. At week 48, 46% of participants reported experiencing some form of PrEP-directed judgment, 23% reported being called “PrEP whore,” and 21% avoiding disclosing PrEP use. Conclusion Over 48 weeks, nearly half of participants reported some form of judgment or stigmatization as a consequence of PrEP use. However, individuals more frequently perceived positively framed reactions to being on PrEP than negative. Importantly, long-term PrEP adherence does not appear to suffer as a result of negative PrEP framing. Disclosures All authors: No reported disclosures.

An improved de Laval nozzle experiment

2021 ◽  
pp. 030641902110341
Author(s):  
Nicholas Goodman ◽  
Brian J Leege ◽  
Peter E Johnson
Keyword(s):  
Data Acquisition ◽  
Laval Nozzle ◽  
Flow Characteristics ◽  
Data Acquisition System ◽  
Isentropic Flow ◽  
Hands On ◽  
De Laval Nozzle ◽  
Physical Phenomena ◽  
The Impact ◽  
The Relationship

Exposing students to hands-on experiments has been a common approach to illustrating complex physical phenomena that have been otherwise modelled solely mathematically. Compressible, isentropic flow in a duct is an example of such a phenomenon, and it is often demonstrated via a de Laval nozzle experiment. We have improved an existing converging/diverging nozzle experiment so that students can modify the location of the normal shock that develops in the diverging portion to better understand the relationship between the shock and the pressure. We have also improved the data acquisition system for this experiment and explained how visualisation of the standing shock is now possible. The results of the updated system demonstrate that the accuracy of the isentropic flow characteristics has not been lost. Through pre- and post-laboratory quizzes, we show the impact on student learning as well.

The flow characteristics around bridge piers under the impact of a ship

2020 ◽  
Vol 32 (6) ◽  
pp. 1165-1177
Author(s):  
Yan-fen Geng ◽  
Hua-qiang Guo ◽  
Xing Ke
Keyword(s):  
Flow Characteristics ◽  
Bridge Piers ◽  
The Impact
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