USE OF FREEWAY CONFLICT RATES AS AN ALTERNATIVE TO CRASH RATES IN WEAVING SECTION SAFETY ANALYSES
Traffic safety is an important concept in the evaluation of a transportation system and its impact on public health. Using reported crash rates as an indicator of safety of a freeway facility has many drawbacks, such as errors in the reporting and recording of crashes, inaccuracies in the way in which the exposure measure is derived, and the wait involved for a sufficient sample size to materialize. Conflict rates provide an alternative to crash rates as an indicator of safety. Benefits of their use include the ease and accuracy with which conflict rates at ramp weaves can be obtained and the high frequency at which they occur with no physical harm to the public. Computer subroutines were added to the Integrated Traffic Simulation (INTRAS) to count conflicts, and freeway traffic was simulated at 10 modeled ramp weaves on Interstate 294 (Interstate 294 serves as a quasi-beltway for the Chicago metropolitan area). The resulting conflict rates were then noted. Volume, geometric, and crash data for the 10 sites were provided by the Illinois State Toll Highway Authority and on-site visits. The conflict rates at the sites were applied in a test of their ability to identify the known hazardous ramp weaves, and the relationship between conflict and crash rates was examined.
This paper appears in Transportation Research Record No. 1401, Highway and Traffic Safety and Accident Research, Management, and Issues.
Transportation Research Board
500 Fifth Street, NW
Rouphail, N M
Transportation Research Record
Figures (3) ; References (8) ; Tables (5)
Old TRIS Terms:
Highways; Research; Safety and Human Factors; I81: Accident Statistics; I82: Accidents and Transport Infrastructure
TRIS, TRB, ATRI
Dec 28 1993 12:00AM
More Articles from this Serial Issue: