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.
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.
Apparently money has been set aside for a new study - but when?