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                Observational Before-After Studies in Road Safety
**Applicability:**
        Analyze
    
          **Description:**
        This three part monograph enables road safety researchers and professionals to correctly interpret the results of one of the main sources of knowledge about the effect of road safety engineering measures, the observational before-after study. Part I contains information the author considers essential for forming an opinion about results obtained by others, and for planning and analyzing such a study. This first part is written to be understood by all road safety professionals. Part II adapts conventional approaches to observational studies. The study of conventional approaches is important because methodologies based on randomized statistical experiments are often inappropriate in road safety research. Part III presents new approaches to improve conventional methods of observational before-after studies. The Empirical Bayes approach (which is the current state of the practice) is presented in Part III.
    
          **Tool Type:**
        Research Publication
    
    
    
          **Owner Source:**
        private_company
    
    
        **Published:**
      2008
    
        **Availability:**
      This book may be borrowed for free from several libraries or purchased for a fee at this link: 2008 Ed. Observational before--after studies in road safety : estimating the effect of highway and traffic engineering measures on road safety.
    
          **Disclaimer:**
        This information is disseminated under the sponsorship of the U.S. Department of Transportation in the interest of information exchange. The U.S. Government assumes no liability for the use of the information contained herein. This information does not constitute a standard, specification, or regulation. The U.S. Government does not endorse products or manufacturers. Trademarks or manufacturer's names appear in this information only because they are considered essential to the objective of this publication.
          Any opinions, findings, and conclusions or recommendations, and translations thereof, expressed in this publication are those of the author(s) and do not necessarily reflect the views of the Federal Highway Administration. U.S. DEPARTMENT OF TRANSPORTATION

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