Exploring the transferability of crash modification factors – Ontario case studies
Author(s): Taha Saleem, Lei Qin, Shahram Almasi, Bhagwant Persaud, Craig Lyon
Slidedeck Presentation :
Abstract:
Background/Context: Most crash modification factors (CMFs) in the Highway Safety Manual are developed based on US data from a few jurisdictions and most at the moment are single valued, a reality that is recognized as problematic. To apply them to another jurisdiction requires an assessment of transferability and possibly an adjustment to reflect different application circumstances.
Aims/Objectives: To use Ontario crash, traffic and geometric data in case studies to assess whether selected CMFs are applicable.
Methods/Target Group: CMFs from before-after and cross-sectional data are estimated from Ontario data and compared to CMFs from other studies applied to the same data. Where the comparison is favourable, CMFs from other studies are updated, where possible, with the Ontario CMF information. CMFs for three treatments -- passing lane installation and length, dual centre line and shoulder rumble strips, and lengthening speed changes lanes are explored.
Results/Activities: These are expected in early January in time for writing a possible paper. At the very least the assessment method will be documented and illustrated.
Discussion/Deliverables: The research will serve as a guideline for Canadian and other jurisdictions to decide on values of CMFs for application to their own circumstances.
Conclusions: Expected in early January. Preliminary results indicate that Ontario-specific CMFs that incorporates knowledge from other CMFs with Ontario data would be developed for at least one treatment.