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

A Comprehensive Discrete Choice Analysis of Injury Severity in Roadway Work Zone Crashes
Author: Mohamed Osman
Publisher:
Total Pages:
Release: 2016
Genre:
ISBN:

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).

Study on Crash Characteristics and Injury Severity at Roadway Work Zones

Study on Crash Characteristics and Injury Severity at Roadway Work Zones
Author: Qing Wang
Publisher:
Total Pages:
Release: 2009
Genre:
ISBN:

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

Work Zone Crash Analysis and Modeling to Identify Factors Associated with Crash Severity and Frequency
Author: Sunanda Dissanayake
Publisher:
Total Pages: 0
Release: 2015
Genre: Roads
ISBN:

"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).

Statistical and Econometric Methods for Transportation Data Analysis

Statistical and Econometric Methods for Transportation Data Analysis
Author: Simon Washington
Publisher: CRC Press
Total Pages: 496
Release: 2020-01-30
Genre: Technology & Engineering
ISBN: 0429520751

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.

Managing Speed

Managing Speed
Author:
Publisher: Transportation Research Board
Total Pages: 444
Release: 1998
Genre: Business & Economics
ISBN: 9780309065023

TRB Special Report 254 - Managing Speed: Review of Current Practices for Setting and Enforcing Speed Limits reviews practices for setting and enforcing speed limits on all types of roads and provides guidance to state and local governments on appropriate methods of setting speed limits and related enforcement strategies. Following an executive summary, the report is presented in six chapters and five appendices.

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

Investigating Impact of Work Zones on Crash Frequency, Severity and Traffic
Author: Ozgur Ozturk
Publisher:
Total Pages: 231
Release: 2014
Genre: Road work zones
ISBN:

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.

A Novel Approach to Modeling and Predicting Crash Frequency at Rural Intersections by Crash Type and Injury Severity Level

A Novel Approach to Modeling and Predicting Crash Frequency at Rural Intersections by Crash Type and Injury Severity Level
Author: Jun Deng (Writer on transportation)
Publisher:
Total Pages: 112
Release: 2013
Genre:
ISBN:

Safety at intersections is of significant interest to transportation professionals due to the large number of possible conflicts that occur at those locations. In particular, rural intersections have been recognized as one of the most hazardous locations on roads. However, most models of crash frequency at rural intersections, and road segments in general, do not differentiate between crash type (such as angle, rear-end or sideswipe) and injury severity (such as fatal injury, non-fatal injury, possible injury or property damage only). Thus, there is a need to be able to identify the differential impacts of intersection-specific and other variables on crash types and severity levels. This thesis builds upon the work of Bhat et al., (2013b) to formulate and apply a novel approach for the joint modeling of crash frequency and combinations of crash type and injury severity. The proposed framework explicitly links a count data model (to model crash frequency) with a discrete choice model (to model combinations of crash type and injury severity), and uses a multinomial probit kernel for the discrete choice model and introduces unobserved heterogeneity in both the crash frequency model and the discrete choice model, while also accommodates excess of zeros. The results show that the type of traffic control and the number of entering roads are the most important determinants of crash counts and crash type/injury severity, and the results from our analysis underscore the value of our proposed model for data fit purposes as well as to accurately estimate variable effects.

Comprehensive Costs of Highway-Rail Grade Crossing Crashes

Comprehensive Costs of Highway-Rail Grade Crossing Crashes
Author: Daniel Brod
Publisher: Transportation Research Board
Total Pages: 119
Release: 2013
Genre: Highway-railroad grade crossings
ISBN: 0309283485

"TRB's National Cooperative Highway Research Program (NCHRP) Report 755: Comprehensive Costs of Highway-Rail Grade Crossing Crashes describes a process for estimating the costs of highway-rail grade crossing crashes. A spreadsheet-based tool to facilitate use of the cost estimation process is available online." --Publisher description.

Logit and Probit

Logit and Probit
Author: Vani K. Borooah
Publisher: SAGE
Total Pages: 108
Release: 2002
Genre: Mathematics
ISBN: 9780761922421

Many problems in the social sciences are amenable to analysis using the analytical tools of logit and probit models. This book explains what ordered and multinomial models are and also shows how to apply them to analysing issues in the social sciences.