Author: Ghazan KhanPublisher:
ISBN:
Category :
Languages : en
Pages : 408
Book Description
A Comprehensive Procedure for Analyzing Road Weather Safety
Author: Ghazan KhanSafety Effects of Road Weather Information Systems (RWIS)
Author: Davesh SharmaPublisher:
ISBN:
Category : Automobile driving in winter
Languages : en
Pages : 0
Book Description
In countries like Canada and the United States, where most of the population lives in snowy regions, winter road maintenance (WRM) has become a significant challenge. Hundreds of people are killed, and thousands are injured every year due to inclement winter weather conditions. To combat this, transportation agencies spend a significant amount of their budget on conducting and maintaining WRM activities. Considering their limited budget and resources, it is indispensable to strategize their investments in equipment, labour, and material without jeopardizing commuter safety. One of the most advanced techniques used for efficient mobilization of WRM services is Road Weather Information Systems (RWIS) - a critical highway intelligent transportation system (ITS) infrastructure. These systems have long been favoured by many North American and European highway authorities as they provide real-time and near-future road condition information collected using roadside sensors during the winter months. Information disseminated by individual RWIS stations is collectively used not only to proficiently organize WRM operations but also to promote safe travel and provide traveller information during adverse weather events. However, the high installation and operational costs of RWIS have necessitated the need to quantify their cost-effectiveness, particularly in improving traffic safety. Limited past efforts have been made to quantify the sole benefits of RWIS, but most analyses were either qualitative in nature or used a naïve safety evaluation technique that resulted in generating less conclusive findings. Acknowledging the importance of determining their benefits as well as a large gap that exists in current methodologies, this thesis aims to develop a unique methodological framework that can be readily used to evaluate and quantify the sole safety effects of RWIS. In particular, this thesis attempts to tackle and answer two research questions: first, whether implementing RWIS stations reduces winter weather collisions and how much reduction can be expected; second, whether RWIS stations are a cost-effective countermeasure with explicit monetary benefits. These questions were answered by conducting a safety evaluation of RWIS stations and an economic analysis. Safety evaluation of RWIS stations was conducted by using one of the most established and statistically defendable methods used in traffic safety studies, namely, the before-and-after Empirical Bayes (EB) approach was used to perform safety evaluation of RWIS stations. A methodology was developed, and a state-wide investigation of RWIS stations in the state of Iowa was conducted. Geographic Information Science (GIS) based techniques were used for the preparation of intensive geospatial datasets required for calibration and validation of safety performance function (SPF). Furthermore, Yearly Calibration Factors (YCFs) were also locally calibrated using large-scale spatial data, where network-based service area analysis using GIS played a crucial role in selecting treatment and reference sites. The results of safety evaluation were used to conduct a detailed economic analysis and Benefit-to-Cost ratios (BCRs) were estimated as a parameter to assess the economic viability of RWIS stations. One-time installation cost, operations cost, and up-gradation cost for each RWIS station were compared with the monetary value safety benefits. Utilizing the developed methodology in this thesis, the sole effectiveness of implementing RWIS was quantified to establish RWIS as a safety countermeasure. The findings from the case study showed safety effectiveness of RWIS that ranged from 31.53% to 88.23%, whereby implying that a significant portion of winter weather collisions was reduced after RWIS implementation. The BCRs of the stations ranged from 7.51 to 34.16, indicating a significant amount of safety benefits compared to the cost of RWIS. The research findings suggest that RWIS stations are an economically viable safety countermeasure, and that transportation professionals and highway authorities can now make more informed decisions on furthering RWIS implementations to improve the safety and mobility of the winter traveling public. The main contributions of this thesis are three-fold. First, the safety effectiveness of RWIS stations was quantified for the first time in the literature using the state-of-the-art EB method with large-scale and multi-year datasets. Second, SPF was locally developed during the process, which is transferable and can be readily used for safety investigations at regions with similar geographical and weather characteristics. Finally, the economic viability of RWIS was quantified using a formal economic analysis at high granularity, which has been absent from the RWIS literature.
Selection of Traffic Controls for Severe Weather Conditions
Author: R J. RourkePublisher:
ISBN:
Category : Traffic engineering
Languages : en
Pages : 220
Book Description
This manual provides guidelines for the selection of traffic controls to reduce the hazards created by severe weather conditions to travel on limited-access highways. Analytical techniques are described in procedural format, along with worksheets, for use by traffic engineers in quantifying the extent of the accident or delay hazard created by extreme weather conditions. A methodology for selection of the most appropriate traffic control is presented based on estimating the level of effectiveness that must be achieved by a control in order to be cost effective. Summary descriptions of traffic controls implemented by the States under various adverse weather conditions, and a comprehensive annotated bibliography are provided in appendices to the report.
Gravel Roads
Author: Ken SkorsethPublisher:
ISBN:
Category : Gravel roads
Languages : en
Pages : 112
Book Description
The purpose of this manual is to provide clear and helpful information for maintaining gravel roads. Very little technical help is available to small agencies that are responsible for managing these roads. Gravel road maintenance has traditionally been "more of an art than a science" and very few formal standards exist. This manual contains guidelines to help answer the questions that arise concerning gravel road maintenance such as: What is enough surface crown? What is too much? What causes corrugation? The information is as nontechnical as possible without sacrificing clear guidelines and instructions on how to do the job right.
Weather Impacts on Transportation Safety
Author: Terrance JacksonPublisher:
ISBN: 9781321735390
Category : Rain and rainfall
Languages : en
Pages : 153
Book Description
Traffic safety and rain-related crashes are a major concern for engineers, planners, and emergency officials. Texas has more roads than any other state; therefore, the study of the factors that cause crashes is crucial to reducing the risk. Traffic safety is significantly impacted by weather conditions. This study contributed to transportation safety by providing an in-depth analysis of rain-related crashes in Texas. The first study used fatal crash data and Geographic Information Systems (GIS) to explore the spatial and temporal distribution of rain-related fatal crashes. The Getis-Ord Gi* statistic was used to identify clear and distinct spatial clustering patterns of rain-related fatal crashes and their correlation with rainfall. Fatal crash data were obtained from the Fatality Analysis Reporting System (FARS) website maintained by the National Highway Traffic Safety Administration. The spatial statistical analysis revealed the spatial patterns of rain-related fatal crashes that are clustered in different counties depending upon rain conditions. The second study contributed to traffic safety by assessing the impact of rain and by conducting a statistical analysis of FARS crashes from 1982 to 2011. Logistic regression was used to identify the dominant factors associated with rain-related fatal crashes. The rain-related crash factors were categorized and examined at the state and county levels and were classified as environmental-related, roadway-related or driver-related. This study results can be used to aid the traffic safety professionals in the planning and design of roads. The final study adopted a matched-pair model to quantify the relative crash risk ratio during rainy conditions on two different areas in Texas: a segment of an interstate highway and an urban center from 2006 to 2013. Crash data were extracted from the Crash Records Information System database maintained by the Texas Department of Transportation. Hourly rainfall data was obtained from the National Weather Service's West Gulf River Forecast Center Multisensor Precipitation Estimates. Comparison of crashes during paired dry and rainy periods indicates that the relative risk ratio during rainy periods was greater than 1.0 for all road segments during the entire analysis period. The results indicate that rain conditions increase the crash risk when other factors are kept constant. The knowledge gained from this matched-pair study can be used to reduce rain-related crashes and further traffic safety countermeasures. The first method used in this research was aimed to study the spatial distribution of rain-related fatal crashes at the county level. The second method used in this study was aimed to use logistic regression to identify rain-related crash factors for Texas at the state and county levels. The third method used in this study was aimed to quantify relative crash risk at a fine resolution with a matched-pair method. The methodology developed in this research to gather and analyze crash data at the state, county, and road segment levels can be used to identify the causes of and reduce rain-related crashes. The benefits of this approach are discussed in more detail in the conclusions and recommendations.
Feasibility Study - National Center for Statistical Analysis of Highway Operations. Highway Safety Act of 1973 (section 213). Volume II. Technical Report. A Report to Congress from the Secretary of Transportation
Author: 
Author: Publisher: Springer Nature
ISBN: 9464635142
Category :
Languages : en
Pages : 899
Book Description
Author: 
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