This Final Report documents a research effort to develop improved safety performance functions (SPFs) for signalized intersections in the State of Oregon. In particular, this research effort focused on the relationship between the physical characteristics of the signalized intersection, the crash history at each location, and the approach speed (represented by speed limit). In additional to developing SPFs for signalized intersection crash prediction for total crashes and severe injury crashes, the research also included an estimation procedure for minor road annual average daily traffic (AADT) values. The research team also re-assessed and ultimately developed a reliable procedure as to how to define an intersection-related crash. Chapter 1 introduces the project and reviews the specific objectives of this research effort. Chapter 2 of this report includes a literature review summarizing the many known factors that influence crashes at signalized intersections as well as current estimation procedures for crashes and AADT values. Chapter 3 then presents an overview of the site selection and final sites selected for the SPF development and validation activities. Chapter 4 reviews the method developed for estimating minor road traffic volumes, and Chapter 5 similarly presents the analysis method and findings for defining intersection-related crashes and then developing SPFs for total and severe injury crashes. The report concludes with Chapter 6 (summary of findings), Chapter 7 (references), and Appendices A - D. (Author/publisher)
Samenvatting