Investigating Impact Of Work Zones On Crash Frequency Severity And Traffic

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Investigating Impact of Work Zones on Crash Frequency, Severity and Traffic

Author : Ozgur Ozturk
Publisher :
ISBN 13 :
Total Pages : 231 pages
Book Rating : 4.:/5 (889 download)

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Book Synopsis Investigating Impact of Work Zones on Crash Frequency, Severity and Traffic by : Ozgur Ozturk

Download or read book Investigating Impact of Work Zones on Crash Frequency, Severity and Traffic written by Ozgur Ozturk and published by . This book was released on 2014 with total page 231 pages. Available in PDF, EPUB and Kindle. Book excerpt: Work zone presence is an important concern for drivers in terms of safety and congestion. In recent years, work zone safety has received much attention due to numerous highway renovation projects that have resulted in many work zone crashes. To minimize the effect of work zones on roadway safety risks and traffic conditions, potential factors need to be addressed and countermeasures need to be implemented to ensure that the motorist can drive in a safe manner. The impact of the work zones can be estimated by using descriptive analysis and different statistical modeling methods. To this end, this study focused on three major areas: the crash frequency at work zones, the crash severity at work zones and the change in traffic conditions at work zones. Statistically robust models were developed by incorporating integrated datasets that could identify significant factors affecting each of these study areas. To better understand this, different from the previous studies, model results were compared against reference conditions, such as work zone crash frequency and modeling parameters were compared with non-work zone parameters. In addition, different statistical modeling techniques were applied to examine the best model or set of variables to connect crash severity and possible causative factors for binary level and multiple level outcomes. Two crash severity indexes were proposed and used to estimate multilevel crash severity by using both maximum severity and the monetary cost weighted severity. Besides safety issues, different types of lane closures and crashes observed within lane closures were studied to examine if there would be a change in traffic conditions compared with normal time traffic. Comparisons of each concept provides an idea for agencies about the differences of work zone and non-work zone conditions which is important if indeed there is a specific impact for the work zone cases. Work zone presence was found to have an increasing effect on crash occurrence. Nighttime shifts were found to be safer when compared to daytime work zone periods. Injury crashes for two-lane closure cases were found to have a more marked impact on traffic volume compared with other cases studied in this dissertation. In the conclusions chapter, all of these findings are summarized along with specific recommendations.

Study on Crash Characteristics and Injury Severity at Roadway Work Zones

Author : Qing Wang
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (436 download)

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Book Synopsis Study on Crash Characteristics and Injury Severity at Roadway Work Zones by : Qing Wang

Download or read book Study on Crash Characteristics and Injury Severity at Roadway Work Zones written by Qing Wang and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT: In USA, despite recent efforts to improve work zone safety, the number of crashes and fatalities at work zones has increased continuously over several past years. For addressing the existing safety problems, a clear understanding of the characteristics of work zone crashes is necessary. This thesis summarized a research study focusing on work zone traffic crash analysis to investigate the characteristics of work zone crashes and to identify the factors contributing to injury severity at work zones. These factors included roadway design, environmental conditions, traffic conditions and vehicle/driver features. Especially, special population groups, which divided into older, middle Age, and young, were inspected. This study was based on history crash data from the Florida State, which were extracted from the Florida CAR (Crash Analysis Reporting) system. Descriptive statistics method was used to find the characteristics of crashes at work zones. After then, an injury severity predict model, using the ordered probit regression technology, was developed to investigate the impacts of various factors on different the injury severity at work zones. From the model, it can be concluded that some factors, including the road section with curve, alcohol/drugs involved, a high speed, angle crash and too young or old drivers are more likely to increase the probability of angle crashes. Based on the magnitudes of the variable coefficients, the factor of maximum posted speed have a great impact to injury severity, which shows restriction to driving speed is principle countermeasure for improving work zone safety.

Work Zone Crash Analysis and Modeling to Identify Factors Associated with Crash Severity and Frequency

Author : Sunanda Dissanayake
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (97 download)

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Book Synopsis Work Zone Crash Analysis and Modeling to Identify Factors Associated with Crash Severity and Frequency by : Sunanda Dissanayake

Download or read book Work Zone Crash Analysis and Modeling to Identify Factors Associated with Crash Severity and Frequency written by Sunanda Dissanayake and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The safe and efficient flow of traffic through work zones must be established by improving work zone conditions. Therefore, identifying the factors associated with the severity and the frequency of work zone crashes is important. According to current statistics from the Federal Highway Administration, 2,372 fatalities were associated with motor vehicle traffic crashes in work zones in the United States during the four years from 2010 to 2013. From 2002 to 2014, an average of 1,612 work zone crashes occurred in Kansas each year, making it a serious concern in Kansas. The objectives of this study were to analyze work zone crash characteristics, identify the factors associated with crash severity and frequency, and to identify recommendations to improve work zone safety. Work zone crashes in Kansas from 2010 to 2013 were used to develop crash severity models. Ordered probit regression was used to model the crash severities for daytime, nighttime, multi-vehicle and single-vehicle work zone crashes and for work zones crashes in general. Based on severity models, drivers from 26 to 65 years of age were associated with high crash severities during daytime work zone crashes and driver age was not found significant in nighttime work zone crashes. The use of safety equipment was related to reduced crash severities regardless of the time of the crash. Negative binomial regression was used to model the work zone crash frequency using work zones functioned in Kansas in 2013 and 2014. According to results, increased average daily traffic (AADT) was related to higher number of work zone crashes and work zones in operation at nighttime were related to a reduced number of work zone crashes. Findings of this study were used to provide general countermeasure ideas for improving safety of work zones" (page ii).

Crash Characteristics at Work Zones

Author : Nicholas J. Garber
Publisher :
ISBN 13 :
Total Pages : 44 pages
Book Rating : 4.3/5 (91 download)

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Book Synopsis Crash Characteristics at Work Zones by : Nicholas J. Garber

Download or read book Crash Characteristics at Work Zones written by Nicholas J. Garber and published by . This book was released on 2002 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: Work zones tend to cause hazardous conditions for drivers and construction workers since they generate conflicts between construction activities and traffic. A clear understanding of the characteristics of work zone crashes will enhance the selection of the appropriate measures that can minimize the negative impacts of work zones. This study investigated the characteristics of work zone crashes that occurred in Virginia between 1996 and 1999. The information on each crash was obtained from the police crash record. The location of each crash was categorized as being in one of the five areas of a typical work zone: advance warning area, transition area, longitudinal buffer area, activity area, and termination area. An analysis of the percentage distributions was then carried out with respect to area in work zone, severity, type of collision, and type of highway. The proportionality test was used to determine significant differences at the 5 percent significance level. Selected crash characteristics, such as the proportions of single- and multi-vehicle crashes, were compared for work zone and non-work zone crashes. The results indicated that the activity area was the predominant location for work zone crashes regardless of highway type and that rear-end crashes were the predominant type of crash. The results also indicated that the proportion of sideswipe same direction crashes in the transition area was significantly higher than in the advance warning area and that work zone crashes involved a higher proportion of multi-vehicle crashes and fatal crashes than did non-work zone crashes.

Socialization of Safety

Author : Rebeka Yocum
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (133 download)

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Book Synopsis Socialization of Safety by : Rebeka Yocum

Download or read book Socialization of Safety written by Rebeka Yocum and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Traffic safety has been a research topic of interest for decades. While research focuses on advanced statistical methods to analyze crash data and predict safety trends, there is also a push to understand the degree to which marginalized communities disproportionately experience traffic safety issues. Existing literature introduces measures of socioeconomic status as explanatory variables used to predict crash frequency, severity, risk, and cost. Although the intersection of socioeconomics and safety has been included in recent research, a more holistic analysis of how wealth-related measures impact county-level safety across multiple safety outcomes is needed. This dissertation substantiates and expands upon existing work investigating the relationship between socioeconomics and traffic safety at a regional level in the state of Pennsylvania. This was done using a multi-faceted approach to understanding of traffic safety in Pennsylvania across various dimensions (crash frequency, crash severity, and crash risk), as well as estimated regional level crash costs which were used to visualize the variability of the economic impact following a crash. Understanding the disproportionate way communities experience the physical and economic impacts of traffic safety is a key first step in providing necessary resources to communities in need. This dissertation presents a concise review of the relationships between socioeconomics and crash frequency, severity, risk, and cost in Pennsylvania. Simply put, regions with higher levels of socioeconomic distress (quantified using different combinations of unemployment and poverty rates, as well as household income and vehicle ownership data) are estimated to experience more crashes, more severe crashes, and higher crash costs. This work also reveals a relationship between crash risk and household income, indicating counties with higher proportions of low-income households are predicted to have higher proportions of registered drivers that are prime factors in crashes occurring in Pennsylvania. This work serves as a broad foundation from which support for the conduction of further research and consideration of equitable transportation safety policies can be drawn.

The Effect of Vehicle Mix on Crash Frequency and Crash Severity

Author : Naveen Eluru
Publisher :
ISBN 13 : 9780309709460
Total Pages : 0 pages
Book Rating : 4.7/5 (94 download)

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Book Synopsis The Effect of Vehicle Mix on Crash Frequency and Crash Severity by : Naveen Eluru

Download or read book The Effect of Vehicle Mix on Crash Frequency and Crash Severity written by Naveen Eluru and published by . This book was released on 2024 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Crash prediction analysis focuses on identifying attributes that result in traffic crashes and proposes effective countermeasures to improve the roadway design and operational attributes. These crash frequency models are typically employed for examining crash counts either at the micro- (intersection or segment) or the macro-level (county or traffic analysis zone).NCHRP Research Report 1103: The Effect of Vehicle Mix on Crash Frequency and Crash Severity, from TRB's National Cooperative Highway Research Program, aimed to develop methods to quantify the impact of vehicle mix on crash frequency and crash severity by facility type and develop a spreadsheet tool for practitioners to quantify the effect of vehicle mix on safety performance."--Publisher's website

Safety Investigation of Traffic Crashes Incorporating Spatial Correlation Effects

Author : Khalid Faleh Alkahtani
Publisher :
ISBN 13 :
Total Pages : 139 pages
Book Rating : 4.:/5 (14 download)

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Book Synopsis Safety Investigation of Traffic Crashes Incorporating Spatial Correlation Effects by : Khalid Faleh Alkahtani

Download or read book Safety Investigation of Traffic Crashes Incorporating Spatial Correlation Effects written by Khalid Faleh Alkahtani and published by . This book was released on 2018 with total page 139 pages. Available in PDF, EPUB and Kindle. Book excerpt: Therefore, in this research, several statistical methods are used to investigate the association between traffic crash frequency and contributing factors of crash data, which are characterized by 1) geographical referencing (i.e., observed at specific locations) or spatially varying over geographic units when modeled; 2) correlation between different response variables (e.g., crash counts by severity or type levels); and 3) temporally correlated. A Bayesian multivariate spatial model is developed for predicting crash counts by severity and type. Therefore, based on the findings of this study, policy makers would be able to suggest appropriate safety countermeasures for each type of crash in each zone.

Statistical and Econometric Methods for Transportation Data Analysis

Author : Simon Washington
Publisher : CRC Press
ISBN 13 : 0429520751
Total Pages : 496 pages
Book Rating : 4.4/5 (295 download)

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Book Synopsis Statistical and Econometric Methods for Transportation Data Analysis by : Simon Washington

Download or read book Statistical and Econometric Methods for Transportation Data Analysis written by Simon Washington and published by CRC Press. This book was released on 2020-01-30 with total page 496 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book's website (with databases and other support materials) can be accessed here. Praise for the Second Edition: The second edition introduces an especially broad set of statistical methods ... As a lecturer in both transportation and marketing research, I find this book an excellent textbook for advanced undergraduate, Master’s and Ph.D. students, covering topics from simple descriptive statistics to complex Bayesian models. ... It is one of the few books that cover an extensive set of statistical methods needed for data analysis in transportation. The book offers a wealth of examples from the transportation field. —The American Statistician Statistical and Econometric Methods for Transportation Data Analysis, Third Edition offers an expansion over the first and second editions in response to the recent methodological advancements in the fields of econometrics and statistics and to provide an increasing range of examples and corresponding data sets. It describes and illustrates some of the statistical and econometric tools commonly used in transportation data analysis. It provides a wide breadth of examples and case studies, covering applications in various aspects of transportation planning, engineering, safety, and economics. Ample analytical rigor is provided in each chapter so that fundamental concepts and principles are clear and numerous references are provided for those seeking additional technical details and applications. New to the Third Edition Updated references and improved examples throughout. New sections on random parameters linear regression and ordered probability models including the hierarchical ordered probit model. A new section on random parameters models with heterogeneity in the means and variances of parameter estimates. Multiple new sections on correlated random parameters and correlated grouped random parameters in probit, logit and hazard-based models. A new section discussing the practical aspects of random parameters model estimation. A new chapter on Latent Class Models. A new chapter on Bivariate and Multivariate Dependent Variable Models. Statistical and Econometric Methods for Transportation Data Analysis, Third Edition can serve as a textbook for advanced undergraduate, Masters, and Ph.D. students in transportation-related disciplines including engineering, economics, urban and regional planning, and sociology. The book also serves as a technical reference for researchers and practitioners wishing to examine and understand a broad range of statistical and econometric tools required to study transportation problems.

A Comprehensive Discrete Choice Analysis of Injury Severity in Roadway Work Zone Crashes

Author : Mohamed Osman
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (984 download)

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Book Synopsis A Comprehensive Discrete Choice Analysis of Injury Severity in Roadway Work Zone Crashes by : Mohamed Osman

Download or read book A Comprehensive Discrete Choice Analysis of Injury Severity in Roadway Work Zone Crashes written by Mohamed Osman and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Work zones are critical parts of the transportation infrastructure renewal process consisting of rehabilitation of roadways, maintenance, and utility work. Given the specific nature of a work zone (complex arrangements of traffic control devices and signs, narrow lanes, duration) a number of crashes occur with varying severities involving different vehicle sizes. This dissertation proposes a comprehensive discrete choice analysis of injury severity of crashes in work zones on both the crash and occupant levels, in roadway work zones through a comprehensive set of discrete choice econometric frameworks. Robust discrete choice modeling structures are introduced and applied in the field of work zone safety. This dissertation contains three (3) studies representing the empirical analysis conducted to address the following research questions:1. What factors may contribute to the injury severity levels of large-truck crashes in work zones? And what are the robust analytical methods to recognize such factors?2. How do specific work zone configurations affect factors contributing to the levels of injury severity of work zone crashes?3. How does the specific work zone-component-area where a crash has occurred affect factors contributing to the injury severity levels of work zone crashes?The first study investigates the causal factors contributing to injury severity of large truck crashes in work zones. The second study investigates the causal factors contributing to the injury severity of passenger-car occupants for crashes occurring in different work zone configurations (lane closure, lane shift/crossover, shoulder/median, intermittent, and other). The third study investigates the causal factors contributing to driver & rsquo;s injury severity in the different work zone component-areas (advance-warning, transition, activity, and termination areas). The first study compares a comprehensive set of discrete choice modeling structures; Multinomial Logit (MNL) model, Nested Logit (NL) model, Ordered Logit (ORL) model and Generalized Ordered Response Logit (GORL) model. The second and third studies developed the Mixed Generalized Ordered Response Probit (MGORP) modeling framework to conduct the proposed analysis to answer the second and third research questions. The empirical analysis was conducted using work zone crash database in 10 years of the Highway Safety Information System (HSIS).

Analysis of Crash Location and Crash Severity Related to Work Zones in Ohio

Author : Ibrahim Alfallaj
Publisher :
ISBN 13 :
Total Pages : 73 pages
Book Rating : 4.:/5 (9 download)

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Book Synopsis Analysis of Crash Location and Crash Severity Related to Work Zones in Ohio by : Ibrahim Alfallaj

Download or read book Analysis of Crash Location and Crash Severity Related to Work Zones in Ohio written by Ibrahim Alfallaj and published by . This book was released on 2014 with total page 73 pages. Available in PDF, EPUB and Kindle. Book excerpt: Due to growth of vehicle travel using streets and highway systems in the United States, pavement repair and rehabilitation projects have increased. As a result, the presence of work zones has created traffic congestion and has increased the crash risk. The main object of this study was to identify significant factors that contribute to an increase in crash severity in the state of Ohio and recognize the most risk segment within the work zone locations. The work zone segment area is made of : (a) termination area (TA), (b) before the first work zone warning sign area (BWS), (c) advance warning area (AWA), (d) transition area (TSA), (e) activity area (AA). This study used a 5-year crash data from Ohio Department of Public Safety (ODPS) database from 2008 to 2012. In this study, classification tree modeling was used to investigate significant predictor variables of crash severity of work zone related crashes and recognize the most significant crash location within work zone areas in the state of Ohio. Classification tree modeling identified ten important variables (factors) that explain a large amount of the variation in the response variable, crash severity. These predictor variables of work zone crash severity identified include collision type, motorcycle related, work zone crashes type, posted speed limit, vehicle type, speed related, alcohol related, semi-truck related, youth related and road condition. In case of work zone location analysis results, this study identified six significant factors, which include collision type, work zone crash type, posted speed limit, vehicle type, workers present, and age of driver. Collision type is the most significant factor that affects crash severity in a work zone. Likewise, for work zone location, the work-zone crash type was the most significant factor that contributed in increasing the probability of work zone location crashes.

Optimizing Work Zone Practices for Highway Construction Projects

Author : Tarek M. Elghamrawy
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (774 download)

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Book Synopsis Optimizing Work Zone Practices for Highway Construction Projects by : Tarek M. Elghamrawy

Download or read book Optimizing Work Zone Practices for Highway Construction Projects written by Tarek M. Elghamrawy and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent studies indicate that work zones suffer from an increasing trend of deaths and injuries in and around the highway construction areas with an average of 745 fatalities and 40,700 severe injuries per year. To control and minimize work zone fatalities and injuries, the Federal Highway Administration (FHWA), American Association of State Highway and Transportation Officials (AASHTO), and many state Departments of Transportation (DOTs) are seeking to improve the design practices of work zones to reduce work zone crashes. To support this vital and pressing highway safety goal, this research study focuses on analyzing and optimizing existing work zone practices and exploring the effectiveness and efficiency of innovative temporary rumble strips that can be used to minimize crashes in and around highway construction and maintenance projects. The research objectives of this study are to: (1) provide enhanced understanding of the impact of work zone parameters and innovative temporary traffic control devices on the safety of highway construction zones; (2) analyze work zone crashes and current practices to identify potential layout parameters that impact work zone crash occurrence; (3) investigate and quantify the impact of work zone layout parameters on the risk and cost of crash occurrence; (4) optimize work zone setup parameters to minimize total work zone costs including agency, user delay, and expected crash costs; (5) conduct field experiments to analyze the efficiency and constructability of various arrangements of temporary rumble strips prior to and at the edge of work zones; and (6) study and enhance the effectiveness of temporary rumble strips in alerting inattentive drivers prior to and at the edge of work zones. In order to achieve these objectives, the study is conducted in seven major tasks that focus on: (1) conducting a comprehensive literature review; (2) collecting and fusing all available data and reports on work zone crashes in Illinois; (3) analyzing work zone crashes and identifying the probable causes and contributing factors; (4) identifying the impact of layout parameters on risk of crash occurrence; (5) developing an optimization model to minimize total work zone costs including agency cost, user delay cost, and expected work zone crash cost; (6) performing field experiments on temporary rumble strips and evaluate the efficiency of utilization on site; and (7) evaluating the effectiveness of temporary rumble strips prior and at the edge of work zones. The main research developments of this study are expected to have significant impacts on (1) identifying potential work zone parameters and contributing causes that impact work zone crash occurrence; (2) estimating the probability of work zones to encounter severe crashes; (3) quantifying the impact of work zone parameters on the risk levels of crash occurrence; (4) estimating the monetary value of work zone crashes based on work zone layout parameters; (5) searching for and identifying optimal work zone setup solutions that specify segment length, operating speed, TTC policy, and concrete barrier at different operation staring times; (6) developing new efficient prototypes of temporary rumble strips to be utilized prior to and at the edge of work zones; and (7) developing practical guidelines for effective design arrangements of temporary rumble strips. These new developments hold a strong promise to: (a) improve work zone safety for both the travelling public and construction workers; (b) improve current work zone layouts, strategies, and standards; (c) provide a baseline for controlling the risk of crash occurrence due to highway work zones; (d) assist construction planners in identifying optimal work zone setups for highway construction; (e) direct the development of practical recommendations for efficient and effective design arrangements of temporary rumble strips; and (f) reduce work zone crashes in the work area through the implementation of practical temporary rumble strips arrangements.

Varied Applications of Work Zone Safety Analysis Through the Investigation of Crash Data, Design, and Field Studies

Author : Erica Lee Swansen
Publisher :
ISBN 13 :
Total Pages : 137 pages
Book Rating : 4.:/5 (82 download)

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Book Synopsis Varied Applications of Work Zone Safety Analysis Through the Investigation of Crash Data, Design, and Field Studies by : Erica Lee Swansen

Download or read book Varied Applications of Work Zone Safety Analysis Through the Investigation of Crash Data, Design, and Field Studies written by Erica Lee Swansen and published by . This book was released on 2012 with total page 137 pages. Available in PDF, EPUB and Kindle. Book excerpt: Work zone crashes and fatalities have been decreasing since 1994. Yet, according to Fatality Analysis Reporting System, 667 people were killed in highway work zone crashes in 2009. As the United States' infrastructure ages and new roads and highways are constructed less frequently, the need for repairs and alterations to the nation's roadways is continually increasing. This growth ensures that work zones will be a vital piece of design focus in the near future. In order to continue the decreasing trend in work zone crashes, and reduce the still significant number of work zone fatalities, work zones need to continually be examined to identify opportunities for improved safety. This research explored the relationship between work zone related crashes and work zone design and setup. More specifically, existing literature and current standards, compiled with crash report form data in the UMass Safety Data Warehouse and field observations in Massachusetts were integrated to determine the causes and remedies for work zone related crashes. The research examined three critical areas: 1) causation of work zone related crashes in contrast to non-work zone related crashes along with variations of citations as a result of work zone crashes; 2) variations of the work zone definition and the impact on work zone involvement; and 3) analysis of conflict and event studies for small scale work zones to develop a methodology using surrogate measures to identify potential countermeasures leading to improved work zone safety. The results are expected to advance the current state of knowledge with regards to work zone design and setup, resulting in recommended actions for improved work zone analysis and design strategies.

Modeling Crash Severity and Speed Profile at Roadway Work Zones

Author : Zhenyu Wang
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (427 download)

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Book Synopsis Modeling Crash Severity and Speed Profile at Roadway Work Zones by : Zhenyu Wang

Download or read book Modeling Crash Severity and Speed Profile at Roadway Work Zones written by Zhenyu Wang and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT: Work zone tends to cause hazardous conditions for drivers and construction workers since work zones generate conflicts between construction activities and the traffic, therefore aggravate the existing traffic conditions and result in severe traffic safety and operational problems. To address the influence of various factors on the crash severity is beneficial to understand the characteristics of work zone crashes. The understanding can be used to select proper countermeasures for reducing the crash severity at work zones and improving work zone safety. In this dissertation, crash severity models were developed to explore the factor impacts on crash severity for two work zone crash datasets (overall crashes and rear-end crashes). Partial proportional odds logistic regression, which has less restriction to the parallel regression assumption and provides more reasonable interpretations of the coefficients, was used to estimate the models. The factor impacts were summarized to indicate which factors are more likely to increase work zone crash severity or which factors tends to reduce the severity. Because the speed variety is an important factor causing accidents at work zone area, the work zone speed profile was analyzed and modeled to predict the distribution of speed along the distance to the starting point of lane closures. A new learning machine algorithm, support vector regression (SVR), was utilized to develop the speed profile model for freeway work zone sections under various scenarios since its excellent generalization ability. A simulation-based experiment was designed for producing the speed data (output data) and scenario data (input data). Based on these data, the speed profile model was trained and validated. The speed profile model can be used as a reference for designing appropriate traffic control countermeasures to improve the work zone safety.

Advanced Statistical Modeling of the Frequency and Severity of Traffic Crashes on Rural Highways

Author : Irfan Uddin Ahmed
Publisher :
ISBN 13 :
Total Pages : 222 pages
Book Rating : 4.4/5 (387 download)

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Book Synopsis Advanced Statistical Modeling of the Frequency and Severity of Traffic Crashes on Rural Highways by : Irfan Uddin Ahmed

Download or read book Advanced Statistical Modeling of the Frequency and Severity of Traffic Crashes on Rural Highways written by Irfan Uddin Ahmed and published by . This book was released on 2022 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt: The primary objective of practitioners working on traffic safety is to reduce the number and severity of crashes. The Highway Safety Manual (HSM) provides practitioners with analytical tools and techniques to estimate the expected crash frequency and severity with the aim to identify and evaluate safety countermeasures. Expected crash frequency can be estimated using Safety Performance Functions (SPFs) provided in Part C of the HSM. The HSM provides simple SPFs which are developed using the most frequently used crash counts model, the negative binomial regression model. The rural nature of Wyoming highways coupled with the mountainous terrain (i.e., challenging roadway geometry) make the HSM basic SPFs unsuitable to determine crash contributing factors for Wyoming conditions. In this regard, the objective of this study is to implement advanced statistical methods such as the different functional forms of Negative Binomial, and Bayesian approach, to develop crash prediction models, investigate crash contributing factors, and determine the impact of safety countermeasures. Bayesian statistics in combination with the power of Markov Chain Monte Carlo (MCMC) sampling techniques provide frameworks to model small sample datasets and complex models at the same time, where the traditional Maximum Likelihood Estimation (MLE) based methods tend to fail. As such, a novel No-U-Turn Sampler for Hamiltonian Monte Carlo (NUTS HMC) sampling technique in a Bayesian framework was utilized to investigate the crash frequency, injury severity of crashes on the interstate freeways and some rural highways in Wyoming. The Poisson and the Negative Binomial (NB) models are the most commonly used regression models in traffic safety analysis. The advantage of the NB model can be further enhanced by providing different functional forms of the variance and the dispersion structure. The NB-2 is the most common form of the NB model, typically used in developing safety performance functions (SPFs) largely due to the mean-variance quadratic relationship. However, studies in the literature have shown that the mean-variance relationship could be unrestrained. Another introduced formulation of the NB model is NB-1, which assumes that there is a constant ratio linking the mean and the variance of the crash frequencies. A more general type of the NB model is the NB-P model, which does not constrain the mean-variance relationship. Thus, leveraging the power of this unrestrained mean-variance relationship, more accurate safety models could be developed, and these would lead to more accurate estimation of crash risk and benefits of potential solutions. This study will help practitioners to implement advanced methodologies to solve traffic safety problems of rural highways that have plagued the researchers for a long time now. The methodologies proposed in this study will help practitioners to replace the outdated and inefficient traditional models and obtain more accurate traffic safety models to predict crashes and the resulting crash injury severity. Moreover, this research quantified the safety effectiveness of some unique countermeasures on rural highways.

Safety by Design

Author : Daniel C. Murray
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (75 download)

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Book Synopsis Safety by Design by : Daniel C. Murray

Download or read book Safety by Design written by Daniel C. Murray and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: As the U.S. population and economy continue to grow, more pressure is being placed on the nation's road and bridge infrastructure today than at any point in history. This growth has left the nation's system of roads and bridges in a perpetual state of repair. As all motorists are aware, road maintenance and construction work projects often cause significant traffic congestion, as well as contribute to an increasing number of accidents and fatalities. Work zone-related crashes that involve large trucks are often more serious and more likely to result in fatalities. In order to mitigate the consequences of large truck crashes in work zones, research is needed to understand the causes of truck accidents in work zones and from those findings, develop appropriate countermeasures to reduce the frequency and severity of large truck work zone crashes. The American Transportation Research Institute (ATRI) initiated this research to investigate the factors that contribute to truck-involved work zone accidents. The research first looked at characteristics of large truck-involved work zone crashes and found that differences exist in the time of day and day of week of occurrence, as well as the number of vehicles typically involved and the type of crash (rear-end, sideswipe, etc.) for large truck work zone crashes versus all work zone crashes. Additionally, the research identified several work zone geometric and traffic control device considerations which may improve large truck safety in work zones, including lane and shoulder widths, and signage. The research also determined that a number of knowledge gaps still exist as related to the underlying causes or contributory factors related to large truck crashes in work zones, such as exposure, driver behavior, and work zone design. Finally, the research proposes a number of potential countermeasures to improve large truck safety in work zones.

Accident Characteristics at Construction and Maintenance Zones in Urban Areas

Author : Nicholas J. Garber
Publisher :
ISBN 13 :
Total Pages : 98 pages
Book Rating : 4.:/5 (1 download)

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Book Synopsis Accident Characteristics at Construction and Maintenance Zones in Urban Areas by : Nicholas J. Garber

Download or read book Accident Characteristics at Construction and Maintenance Zones in Urban Areas written by Nicholas J. Garber and published by . This book was released on 1990 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: Safety at construction and maintenance zones is now considered as one of the major concerns of traffic and highway engineers, particularly in urban areas where the installation of work zones significantly affect the flow of traffic . This issue is getting more important as greater emphasis is placed on maintenance and rehabilitation work rather than on new construction, resulting in the proliferation of work zones in the nation's highways. Preliminary analysis of accident data at urban workzones in Virginia indicates that accident rates tend to be significantly higher when work zones coupled with the expected increase in traffic volume will result in significant increase in accident rates, unless effective measures are taken to increase safety at these work zones. The identification of effective safety counter measures at urban work zones, however, requires a clear understanding of work zone accident characteristics and knowledge of the effectiveness of different traffic control devices commonly used. A study was therefore conducted to identify the predominant accident characteristics in urban work zones in Virginia and to evaluate the effectiveness of different traffic control devices in reducing the increase in accident rates during periods of work zone activities. This paper presents the results of statistical analyses of accident data for different work zones and the predominant accident characteristics identified from these analyses. While significant increase in accident rates were observed, there was no significant difference observed in type and severity of accidents. For the covering abstract of this Conference see IRRD abstract number 853851.

Highway and Traffic Safety

Author : National Research Council (U.S.). Transportation Research Board
Publisher :
ISBN 13 :
Total Pages : 148 pages
Book Rating : 4.X/5 (4 download)

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Book Synopsis Highway and Traffic Safety by : National Research Council (U.S.). Transportation Research Board

Download or read book Highway and Traffic Safety written by National Research Council (U.S.). Transportation Research Board and published by . This book was released on 2000 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: Transportation Research Record contains the following papers: Method for identifying factors contributing to driver-injury severity in traffic crashes (Chen, WH and Jovanis, PP); Crash- and injury-outcome multipliers (Kim, K); Guidelines for identification of hazardous highway curves (Persaud, B, Retting, RA and Lyon, C); Tools to identify safety issues for a corridor safety-improvement program (Breyer, JP); Prediction of risk of wet-pavement accidents : fuzzy logic model (Xiao, J, Kulakowski, BT and El-Gindy, M); Analysis of accident-reduction factors on California state highways (Hanley, KE, Gibby, AR and Ferrara, T); Injury effects of rollovers and events sequence in single-vehicle crashes (Krull, KA, Khattack, AJ and Council, FM); Analytical modeling of driver-guidance schemes with flow variability considerations (Kaysi, I and Ail, NH); Evaluating the effectiveness of Norway's speak out! road safety campaign : The logic of causal inference in road safety evaluation studies (Elvik, R); Effect of speed, flow, and geometric characteristics on crash frequency for two-lane highways (Garber, NJ and Ehrhart, AA); Development of a relational accident database management system for Mexican federal roads (Mendoza, A, Uribe, A, Gil, GZ and Mayoral, E); Estimating traffic accident rates while accounting for traffic-volume estimation error : a Gibbs sampling approach (Davis, GA); Accident prediction models with and without trend : application of the generalized estimating equations procedure (Lord, D and Persaud, BN); Examination of methods that adjust observed traffic volumes on a network (Kikuchi, S, Miljkovic, D and van Zuylen, HJ); Day-to-day travel-time trends and travel-time prediction form loop-detector data (Kwon, JK, Coifman, B and Bickel, P); Heuristic vehicle classification using inductive signatures on freeways (Sun, C and Ritchie, SG).