Safety Performance of Rural Curved Corner Intersections with Regional Effects

Abstract

This study evaluates the intersection of rural roads where a curved roadway segment connects the major flow of through traffic from orthogonal directions. A system of up to three intersections in combination can be represented singly by the situation modeled in this paper as a curved corner intersection site. This paper evaluates the application of random intercept negative binomial (NB) regression modeling to produce safety performance functions, and compares the outcome with NB models using fixed regional effects. At curved corner intersections, installing a combined/merged intersection approach near the midpoint of the curve is a potential countermeasure that by comparison with three-leg configurations experienced 20% fewer intersection crashes. A larger radius of curvature along the curved segment at these types of intersections is also very favorable for safety performance. Each 100 ft increase in the radius of a three-leg or four-leg curved corner intersection is estimated to reduce total non-animal crash occurrence by 5% and 7%, respectively. This study can help safety engineers to prioritize the improvement of rural un-signalized intersections.

Crash Modification Functions for Rural Skewed Intersections

“…To further isolate high-speed highways, intersections within villages and census-designated places were also excluded. Intersection locations where a curved roadway segment connects the major flow of through-traffic from orthogonal directions, effectively the major road curves at the intersection, were also excluded because these have been separately studied as curved corner sites ( 14 ). A total of 1,498 three-leg and 1,564 four-leg rural minor road stop-controlled intersections were identified along two-lane two-way roadways in the state of Michigan.…”