Police Accident Reports (PAR) reveal that in a 5-year period between 1993 and 1997, there were 892 crashes at 87 two lane, undivided roadway sites in Strafford County, NH, a county consisting of suburban and rural communities. The purpose of this paper is to describe: (1) logistic regression model building efforts to identify statistically significant factors that predict the probabilities of crashes and injury crashes; and (2) to use these models to perform a risk assessment of the study region. The models are functions of factors that describe a site by its land use activity, roadside design, use of traffic control devices and traffic exposure. Comparative risk assessment results show village sites to be less hazardous than residential and shopping sites. Residential and shopping sites, which are distinctly different from village sites, reside in single-purpose, land-use zones consisting mostly of single-family dwelling units and roadside shopping units with ample off-street parking. Village sites reside in multi-purpose, land-use zones permitting a combination of activities found in residential, shopping and commercial areas. They are pedestrian friendly, that is, have sidewalks and crosswalks, permit onstreet parking, have speed limits and other amenities that promote walking. Adjusted odds ratios and other comparative risk measures are used to explain why one site is more hazardous than another one. For example, the probability of a crash is two times more likely at a site without a sidewalk than at a site with one. The implications on roadway design to improve safety are discussed. (Author/publisher).
Abstract