I have carried out a number of analyses for Opus International Consultants on the relationship between road crash (accident) rates and road geometry and surface properties.
This page gives links to some of my reports and papers. Go here for the latest version.
There is an overview of my initial study in 1994-5 in my page Road geometry and accident risk. The results were presented as part of a conference paper Application of the Road Geometry Data Acquisition System (1.9 MB pdf file). This paper uses traffic volumes and road curvature as the main predictors.
As road skid resistance measurements became available the road authorities became interested in the effect of skid resistance on crash rates. My initial analyses were on selected sections of road and two periods of recording. They looked for how changes in the number of crashes related to changes in the skid resistance at each site. Here is my report: Skid resistance and road crashes (73 KB pdf file).
In 2003-4 I did a more comprehensive analysis on the whole state highway network using 6 years of data. This time we had much more comprehensive data and the road skid resistance became an important predictor.
In 2008-9 there was a follow up study using the same data. The new analysis included a term to allow for curves which were "out of context" with the preceding road. There were two versions. The first was a modification of the 2003-4 analysis and the second looked at the curves as units.
In 2010 I did a rerun using the 2000-2009 data and bringing roughness into the model. Go here for my report.