Research Report
Andrew Vogt and Joe Bared
Oct-98
This report describes the collection, analysis, and modeling of accident and roadway data pertaining to segments and intersections on rural roads in the States of Minnesota (1985-1989) and Washington (1993-1995). The segments are two-lane roads, and the intersections are three-legged and four-legged intersections of such roads, stop-controlled on the minor legs. Data were acquired from the Highway Safety Information System, photologs, construction plans, and State databases. More than 1,300 segments and more than 700 intersections are included in the final samples on which the modeling is based. Variables collected include accident counts, traffic exposure, surface and shoulder width, Roadside Hazard Rating, number of driveways, channelization, horizontal and vertical alignments, intersection angles, speed limits, and commercial traffic percentage. Models of Poisson type, negative binomial type, and extended negative binomial type (the latter due to Shaw-pin Miaou) are developed, and advanced statistical techniques are applied to assess the explanatory value of the models in the presence of poisson randomness and overdispersion. The models derived from these data indicate that exposure and traffic counts are the chief highway variables contributing to accidents, but that surface and shoulder width, roadside conditions, and alignments are also significant, especially in the segment models. Unexpected behavior of intersection angle, Roadside Hazard Rating, number of driveways, and channelization in the intersection models is worthy of note. Despite the incompleteness of the data and uncertainties in the values of some variables, the quantity, quality, and variety of the data give the models both descriptive value.
Link not available.
Highway Safety
Accident Prediction Models
Two-Lane Rural Highways
Negative Binomial Model
Extended Negative Binomial Models
Highway Geometric Design
HSIS
HSIS Summary Reports are two to eight pages in length and include a brief description of the issue addressed, data used, methodology applied, significant results, and practical implications.
A variety of research studies have been performed using data from HSIS. Many of the final reports prepared are now available electronically.
Research reports are often summarized in executive summaries, technical briefs, or other abbreviated formats. Included here are those road safety summaries that involved research using HSIS data.
In addition to conducting research, HSIS resources are also used to develop products that can be used by practitioners in the analysis of safety problems.
HSIS data are sometimes used in research studies that result in other types of finished products, such as dissertations, theses, and conference proceedings.
