Study Details

Study Title: Advancing Innovating Intersection Safety Treatments for Two-Lane Rural Highways

Authors: Torbic et al.

Publication Date:DEC, 2015

Abstract: Intersection safety is a national, state, and local priority. Approximately 26 percent of the fatal crashes that occur in the United States are intersection or intersection-related crashes. The objective of this guide is to advance efforts to improve safety at unsignalized intersections with minor-road stop control along rural two-lane roads, by focusing on strategies that are not yet widespread. The safety effectiveness of three low-cost safety treatments was evaluated to estimate their expected effectiveness in reducing crashes. The low-cost safety treatments included: (1) single luminaire intersection lighting, (2) transverse rumble strips in advance of stop-controlled approaches, and (3) supplementary pavement markings on intersection approaches. The effectiveness of each treatment in reducing crashes was estimated using the Empirical Bayes (EB) observational before-after safety evaluation analysis approach. Analyses were performed to estimate the effectiveness of each treatment in reducing crashes for different severity levels and crash types. An economic analysis of the treatments was also performed. Each of the treatments is effective in reducing crashes of different types and severity levels, and is economically justifiable for most traffic volumes. The information in this report can be combined with information on other strategies to reduce intersection or intersection-related crashes at unsignalized intersections with minor-road stop control along rural two-lane roads. With such information, agencies can make informed decisions about planning and programming safety improvements at intersections under their jurisdiction.

Study Citation: Torbic, D.J., D.J. Cook, J.M. Hutton, K.M. Bauer, and J.M. Sitzmann. "Advancing Innovating Intersection Safety Treatments for Two-Lane Rural Highways". FHWA-SA-16-003. Federal Highway Administration. Washington, D.C., (December 2015).

Study Report: Download the Study Report Document


CMFs Associated With This Study

Category: Delineation

Countermeasure: Install supplemental intersection shaped pavement markings

CMF CRF(%)QualityCrash TypeCrash SeverityRoadway TypeArea Type
0.51493 StarsAllK,A,B,CNot specifiedRural
0.54463 StarsAllAllNot specifiedRural
0.25753 StarsRear endONot specifiedRural
0.24763 StarsRear endK,A,B,CNot specifiedRural
0.31693 StarsRear endAllNot specifiedRural
0.65353 StarsAngleONot specifiedRural
0.58423 StarsAngleK,A,B,CNot specifiedRural
0.62383 StarsAngleAllNot specifiedRural
0.5503 StarsAllONot specifiedRural

Countermeasure: Provide "Stop Ahead" pavement markings

CMF CRF(%)QualityCrash TypeCrash SeverityRoadway TypeArea Type
0.04963 StarsRear endK,A,B,CNot specifiedRural
01002 StarsAngleONot specifiedRural
0.12883 StarsAngleK,A,B,CNot specifiedRural
0.08923 StarsAngleAllNot specifiedRural
0.28723 StarsAllONot specifiedRural
0.24763 StarsAllK,A,B,CNot specifiedRural
0.33674 StarsAllAllNot specifiedRural
0.05953 StarsRear endAllNot specifiedRural
0.03973 StarsRear endONot specifiedRural
0.34664 StarsAllAllNot specifiedRural
0.31694 StarsAllK,A,B,CNot specifiedRural
0.23774 StarsAllONot specifiedRural
0.26744 StarsAngleAllNot specifiedRural
0.29714 StarsAngleK,A,B,CNot specifiedRural
0.12884 StarsAngleONot specifiedRural
0.11894 StarsRear endAllNot specifiedRural
0.14863 StarsRear endK,A,B,CNot specifiedRural
0.05953 StarsRear endONot specifiedRural

Category:Highway lighting

Countermeasure: Install single luminaire at intersection

CMF CRF(%)QualityCrash TypeCrash SeverityRoadway TypeArea Type
01002 StarsAll,NighttimeONot specifiedRural
0.29713 StarsAll,NighttimeAllNot specifiedRural
0.79213 StarsAll,NighttimeK,A,B,CNot specifiedRural

Category:Roadway

Countermeasure: Install transverse rumble strips on stop controlled approaches in rural areas

CMF CRF(%)QualityCrash TypeCrash SeverityRoadway TypeArea Type
0.44563 StarsRear endAllNot specifiedRural
0.87133 StarsAngleONot specifiedRural
0.75254 StarsAngleK,A,B,CNot specifiedRural
0.87133 StarsAngleAllNot specifiedRural
0.86143 StarsAllONot specifiedRural
0.71294 StarsAllK,A,B,CNot specifiedRural
0.87133 StarsAllAllNot specifiedRural
0.9463 StarsRear endONot specifiedRural
0.4603 StarsRear endK,A,B,CNot specifiedRural
0.84163 StarsRear endAllNot specifiedRural
0.56443 StarsAngleK,A,B,CNot specifiedRural
0.57433 StarsAngleAllNot specifiedRural
0.87133 StarsAllONot specifiedRural
0.63373 StarsAllK,A,B,CNot specifiedRural
0.82183 StarsAllAllNot specifiedRural
0.46543 StarsRear endONot specifiedRural
0.22783 StarsRear endK,A,B,CNot specifiedRural