Freeway Weaving: Comparison of Highway Capacity Manual 2000 and Dutch Guidelines

2003 ◽  
Vol 1852 (1) ◽  
pp. 10-18 ◽  
Author(s):  
M. M. Minderhoud ◽  
L. Elefteriadou Elefteriadou
Keyword(s):  
United States ◽  
Sensitivity Analysis ◽  
The United States ◽  
Level Of Service ◽  
Highway Capacity ◽  
Highway Capacity Manual ◽  
Additional Variable ◽  
Different Types ◽  
The U.S ◽  
Capacity Estimates

Weaving sections are a commonly adopted freeway facility both in the United States and in Europe. Knowledge about the capacity and level of service achievable on different types of weaving segments is necessary for the design and management of freeways. Guidelines such as those of the U.S. Highway Capacity Manual (HCM) provide capacity values for different weaving configuration types. The Dutch guidelines for the design of weaving segments are compared with those of the U.S. HCM. Differences between their respective approaches are identified, and a comparison of capacity values is conducted. It was found that there are large differences in capacity estimates for certain weaving configuration types. The results of a sensitivity analysis explain these differences in capacity values to a large extent. This analysis showed that it is important to consider the weaving proportions per leg. Currently, neither the HCM nor the Dutch approach considers different weaving flows per incoming leg. The introduction of an additional variable into the calculation procedure that takes into account the presence of asymmetrical weaving flows is recommended.

Uncertainty in Operational Analysis of Two-Lane Highways

2002 ◽  
Vol 1802 (1) ◽  
pp. 105-114 ◽  
Author(s):  
R. Tapio Luttinen
Keyword(s):  
Input Data ◽  
Travel Speed ◽  
Level Of Service ◽  
Model Parameters ◽  
Highway Capacity ◽  
Highway Capacity Manual ◽  
Operational Analysis ◽  
Percent Time ◽  
Different Types ◽  
Percent Time Spent Following

The Highway Capacity Manual (HCM) 2000 provides methods to estimate performance measures and the level of service for different types of traffic facilities. Because neither the input data nor the model parameters are totally accurate, there is an element of uncertainty in the results. An analytical method was used to estimate the uncertainty in the service measures of two-lane highways. The input data and the model parameters were considered as random variables. The propagation of error through the arithmetic operations in the HCM 2000 methodology was estimated. Finally, the uncertainty in the average travel speed and percent time spent following was analyzed, and four approaches were considered to deal with uncertainty in the level of service.

Complexity of Illustrations in PISA-2009 Science Items and Its Relationship to the Performance of Students from Shanghai-China, the United States, and Mexico

2015 ◽  
Vol 117 (1) ◽  
pp. 1-18
Author(s):  
Guillermo Solano-Flores ◽  
Chao Wang
Keyword(s):  
United States ◽  
Student Performance ◽  
Exploratory Study ◽  
Item Difficulty ◽  
Secondary Analysis ◽  
The United States ◽  
Analysis Study ◽  
Science Tests ◽  
Different Types ◽  
The U.S

Background While illustrations are widely used in international test comparisons, very scant research has been conducted on their design and on their influence on student performance. It is not clear how the features of illustration act in combination supporting students’ access to the content of items or increasing their interpretation demands. Purpose The purpose of this study was to examine how the characteristics of illustrations used in science items are related to the performance of students in PISA-2009. Population We used PISA-2009 data on the responses of 1571 to 1582, 1601 to 1617, and 11,662 to 11,746 students, respectively from Shanghai-China, the U.S., and Mexico. Research Design This was a secondary analysis study that compared the three PISA-2009 jurisdictions as to the magnitudes and directions of the correlations between the complexity of illustrations used in science items and the difficulty of those items. We used the information on item difficulty provided by the Organisation for Economic Co-operation and Development (OECD, 2010). The features of the illustrations were coded with a system that coded the presence or absence of about 100 types of illustration features. The complexity of each illustration was computed as the number of different types of features observed. Findings For the U.S. and Mexico, items with higher illustration complexities were more difficult than items with lower illustration complexities. For Shanghai-China, the correlation of number of illustration features and item difficulty was close to zero. This pattern of correlations is consistent with the three jurisdictions’ ranking in PISA-2009. Conclusions While this was an exploratory study that examined the performance of only three of the 65 PISA-2009 jurisdictions, the results speak to the importance of examining illustration complexity as a factor that shapes student performance in science tests and which should be addressed systematically in the design of science items.

Complexity of Illustrations in PISA-2009 Science Items and Its Relationship to the Performance of Students from Shanghai-China, the United States, and Mexico

2015 ◽  
Vol 117 (1) ◽  
pp. 1-18
Author(s):  
Guillermo Solano-Flores ◽  
Chao Wang
Keyword(s):  
United States ◽  
Student Performance ◽  
Exploratory Study ◽  
Item Difficulty ◽  
Secondary Analysis ◽  
The United States ◽  
Analysis Study ◽  
Science Tests ◽  
Different Types ◽  
The U.S

Background While illustrations are widely used in international test comparisons, very scant research has been conducted on their design and on their influence on student performance. It is not clear how the features of illustration act in combination supporting students’ access to the content of items or increasing their interpretation demands. Purpose The purpose of this study was to examine how the characteristics of illustrations used in science items are related to the performance of students in PISA-2009. Population We used PISA-2009 data on the responses of 1571 to 1582, 1601 to 1617, and 11,662 to 11,746 students, respectively from Shanghai-China, the U.S., and Mexico. Research Design This was a secondary analysis study that compared the three PISA-2009 jurisdictions as to the magnitudes and directions of the correlations between the complexity of illustrations used in science items and the difficulty of those items. We used the information on item difficulty provided by the Organisation for Economic Co-operation and Development (OECD, 2010). The features of the illustrations were coded with a system that coded the presence or absence of about 100 types of illustration features. The complexity of each illustration was computed as the number of different types of features observed. Findings For the U.S. and Mexico, items with higher illustration complexities were more difficult than items with lower illustration complexities. For Shanghai-China, the correlation of number of illustration features and item difficulty was close to zero. This pattern of correlations is consistent with the three jurisdictions’ ranking in PISA-2009. Conclusions While this was an exploratory study that examined the performance of only three of the 65 PISA-2009 jurisdictions, the results speak to the importance of examining illustration complexity as a factor that shapes student performance in science tests and which should be addressed systematically in the design of science items.

Lane Utilization Model Development for Diverging Diamond Interchanges

2017 ◽  
Vol 2618 (1) ◽  
pp. 27-37
Author(s):  
Chunho Yeom ◽  
Bastian J. Schroeder ◽  
Christopher Cunningham ◽  
Katy Salamati ◽  
Nagui M. Rouphail
Keyword(s):  
United States ◽  
Field Data ◽  
Model Development ◽  
The United States ◽  
Highway Capacity ◽  
Double Crossover ◽  
Highway Capacity Manual ◽  
Diamond Interchanges ◽  
Lane Utilization ◽  
Analysis Models

The diverging diamond interchange (DDI), also known as the double crossover diamond interchange, has been a successful, if unconventional, solution used in many parts of the United States ever since its first installation in Springfield, Missouri, in June 2009. One of the challenges to agencies in planning and operating DDIs is to apply to them methodologies developed for a conventional diamond interchange. The Highway Capacity Manual 2010 (HCM 2010) provides lane use analysis models for various lane configurations. However, there is no guarantee that these models will work for DDIs. For this reason, 11 DDIs were studied nationwide ( a) to examine whether the current HCM lane use models provided accurate results for DDIs and ( b) to develop new lane use models for them if the HCM models did not work. As a result of the study, unique multiregime lane utilization models were proposed, separated by the number of approach lanes and validated by field data not used in the model development.

scholarly journals Traffic Operations on Rural Two-Lane Highways: A Review on Performance Measures and Indicators

2018 ◽  
Vol 2672 (15) ◽  
pp. 66-74 ◽  
Author(s):  
Ahmed Al-Kaisy ◽  
Amirhossein Jafari ◽  
Scott Washburn ◽  
Tapio Lutinnen ◽  
Richard Dowling
Keyword(s):  
United States ◽  
Performance Measures ◽  
Rural Areas ◽  
Subjective Assessment ◽  
The United States ◽  
Highway Capacity ◽  
Highway Capacity Manual ◽  
Improvement Programs ◽  
Performance Determinants ◽  
Highway Facilities

Two- lane highways constitute a large proportion of the highway system in the United States, particularly in rural areas. Performance evaluation on those highways is the basis for planning, upgrade, and improvement programs. Such evaluations are conducted using performance measures that should ideally be correlated to performance determinants on those highways. Unlike other highway facilities, two-lane highway performance is notably affected by the platooning phenomenon, which is believed to be a function of traffic level and passing opportunities. Over the last couple of decades, several studies have addressed performance measures on two-lane highways, and are mainly driven by the reported limitations of the current measures used by the Highway Capacity Manual (HCM). This review aims to summarize the performance measures that have been published in the literature or used in practice both in the United States and abroad. The review starts with an historical overview of the HCM performance measures since its inception in 1950. It then discusses the most important criteria for measures to be more effective in describing performance, before presenting the review results for measures that have been proposed in literature or reported as being used in practice. Finally, a subjective assessment of all performance measures against the set of criteria outlined in the article is presented. The review presented in this paper provides information that is valuable for practitioners and researchers in understating the alternative measures for assessing performance on two-lane highways, and the limitations and merits associated with those measures.

Safety, Delay, and Capacity of Single-Lane Roundabouts in the United States

1998 ◽  
Vol 1646 (1) ◽  
pp. 63-70 ◽  
Author(s):  
Aimee Flannery ◽  
Lily Elefteriadou ◽  
Paul Koza ◽  
John McFadden
Keyword(s):  
United States ◽  
Field Capacity ◽  
Traffic Signals ◽  
The United States ◽  
Highway Capacity ◽  
Highway Capacity Manual ◽  
Control Delay ◽  
Capacity Model ◽  
Potential Capacity ◽  
Before And After

Roundabouts are a form of at-grade intersection control that is used frequently around the world and is becoming popular in the United States. Roundabouts are being used to replace two-way and all-way stopcontrolled intersections and traffic signals in the United States. Roundabouts have also been used recently in Vail, Colorado, to improve an existing stop-controlled freeway interchange system. In this study, five single-lane roundabouts are studied to assess their safety and operational performance. All five sites were stop-controlled before roundabouts were installed, and overall the sites experienced a reduction in accident frequencies, rates, and also control delay. Aside from a review of safety and delay data before and after installation of the roundabouts, this study includes a comparison of field-measured control delay with that predicted by SIDRA, an analytically based software package that can analyze at-grade sign- and signal-controlled intersections as well as roundabouts. This study will help agencies better understand their ability to predict delay at American roundabouts. Finally, findings are presented regarding the accuracy of the roundabout capacity model contained in the 1997 update to Chapter 10 of the Highway Capacity Manual. Because of the lack of roundabout entries that are operating at capacity in the United States, an approximation of potential capacity based on available gaps in the circulating stream was made. These findings indicate that the manual may be optimistic in its prediction of capacity for single-lane roundabouts in the United States; however, it should be noted that the lack of roundabout entries operating under capacity in the United States only allows for an approximation of field capacity to be made at this time.

An American Language

2018 ◽  
Author(s):  
Rosina Lozano
Keyword(s):  
United States ◽  
National Policy ◽  
The United States ◽  
Spanish Language ◽  
Spanish Speakers ◽  
Language Recognition ◽  
Political Language ◽  
Political Issue ◽  
History Of ◽  
The U.S

An American Language is a political history of the Spanish language in the United States. The nation has always been multilingual and the Spanish language in particular has remained as an important political issue into the present. After the U.S.-Mexican War, the Spanish language became a language of politics as Spanish speakers in the U.S. Southwest used it to build territorial and state governments. In the twentieth century, Spanish became a political language where speakers and those opposed to its use clashed over what Spanish's presence in the United States meant. This book recovers this story by using evidence that includes Spanish language newspapers, letters, state and territorial session laws, and federal archives to profile the struggle and resilience of Spanish speakers who advocated for their language rights as U.S. citizens. Comparing Spanish as a language of politics and as a political language across the Southwest and noncontiguous territories provides an opportunity to measure shifts in allegiance to the nation and exposes differing forms of nationalism. Language concessions and continued use of Spanish is a measure of power. Official language recognition by federal or state officials validates Spanish speakers' claims to US citizenship. The long history of policies relating to language in the United States provides a way to measure how U.S. visions of itself have shifted due to continuous migration from Latin America. Spanish-speaking U.S. citizens are crucial arbiters of Spanish language politics and their successes have broader implications on national policy and our understanding of Americans.

Palestine Unbound

2018 ◽  
Vol 47 (3) ◽  
pp. 130-134
Keyword(s):  
United States ◽  
Human Rights ◽  
Task Force ◽  
The United States ◽  
Donald Trump ◽  
Tel Aviv ◽  
The Us ◽  
Intention To Move ◽  
Arab Israeli Conflict ◽  
The U.S

This section, updated regularly on the blog Palestine Square, covers popular conversations related to the Palestinians and the Arab-Israeli conflict during the quarter 16 November 2017 to 15 February 2018: #JerusalemIstheCapitalofPalestine went viral after U.S. president Donald Trump recognized Jerusalem as the capital of Israel and announced his intention to move the U.S. embassy there from Tel Aviv. The arrest of Palestinian teenager Ahed Tamimi for slapping an Israeli soldier also prompted a viral campaign under the hashtag #FreeAhed. A smaller campaign protested the exclusion of Palestinian human rights from the agenda of the annual Creating Change conference organized by the US-based National LGBTQ Task Force in Washington. And, UNRWA publicized its emergency funding appeal, following the decision of the United States to slash funding to the organization, with the hashtag #DignityIsPriceless.

The French Way

2011 ◽  
Author(s):  
Richard F. Kuisel
Keyword(s):  
United States ◽  
The United States ◽  
French Language ◽  
French Cinema ◽  
Free Markets ◽  
Technology Sector ◽  
Aids Epidemic ◽  
Political Reality ◽  
Politics And Culture ◽  
The U.S

There are over 1,000 McDonald's on French soil. Two Disney theme parks have opened near Paris in the last two decades. And American-inspired vocabulary such as “le weekend” has been absorbed into the French language. But as former French president Jacques Chirac put it: “The U.S. finds France unbearably pretentious. And we find the U.S. unbearably hegemonic.” Are the French fascinated or threatened by America? They Americanize yet are notorious for expressions of anti-Americanism. From McDonald's and Coca-Cola to free markets and foreign policy, this book looks closely at the conflicts and contradictions of France's relationship to American politics and culture. The book shows how the French have used America as both yardstick and foil to measure their own distinct national identity. France has charted its own path: it has welcomed America's products but rejected American policies; assailed Americ's “jungle capitalism” while liberalizing its own economy; attacked “Reaganomics” while defending French social security; and protected French cinema, television, food, and language even while ingesting American pop culture. The book examines France's role as an independent ally of the United States, but he also considers the country's failures in influencing the Reagan, Bush, and Clinton administrations. Whether investigating France's successful information technology sector or its spurning of American expertise during the AIDS epidemic, the book asks if this insistence on a French way represents a growing distance between Europe and the United States or a reaction to American globalization. Exploring cultural trends, values, public opinion, and political reality, this book delves into the complex relationship between two modern nations.

Latino Catholicism

2011 ◽  
Author(s):  
Timothy Matovina
Keyword(s):  
United States ◽  
Sixteenth Century ◽  
Catholic Church ◽  
Social Life ◽  
Social Issues ◽  
The United States ◽  
Societal Impact ◽  
Comprehensive Overview ◽  
Public Debates ◽  
The U.S

Most histories of Catholicism in the United States focus on the experience of Euro-American Catholics, whose views on social issues have dominated public debates. This book provides a comprehensive overview of the Latino Catholic experience in America from the sixteenth century to today, and offers the most in-depth examination to date of the important ways the U.S. Catholic Church, its evolving Latino majority, and American culture are mutually transforming one another. This book highlights the vital contributions of Latinos to American religious and social life, demonstrating in particular how their engagement with the U.S. cultural milieu is the most significant factor behind their ecclesial and societal impact.

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