A research study on the feasibility of developing a quantitative relationship between roadway geometric factors and collision rates was recently undertaken by the University of Alberta and Alberta Transportation and Utilities in order to identify potential 3R/4R (Restoration, Rehabilitation, Resurfacing, and Reconstruction) project guidelines. As part of the project, a survey of all state and provincial transportation agencies within the United States and Canada as well as the federal transportation authorities of England, South Africa, and Australia was conducted to obtain information on procedures for incorporating safety considerations within the 3R/4R geometric design process. Of the 64 agencies surveyed 45 responded with completed forms. The survey consisted of questions regarding the use of accident analysis data and safety design concepts in 3R/4R design guidelines and was divided into four separate sections: (1) general information on 3R/4R design standards; (2) methods of accident data acquisition; (3) accident data analysis; and (4) the use of safety-geometric models to identify and quantify the relationship between safety and roadway geometric features. This paper focuses on elements of the survey results, primarily by highlighting the similarities and differences of regional design practices within North America. Identified from the survey results are the various agencies that currently undertake 3R/4R project work, and any associated safety considerations for doing so. Lastly, agencies that use safety-geometric models in their safety assessment process are identified and their safety-geometric collision modeling practices examined in detail.
Abstract