Evaluation of intersection countermeasures on high-speed rural multi-lane facilities.

Final; July 2007-Jan. 2012.PDFTech ReportFHWAGA-12-0719SPR00-0008-00(628)IntersectionsRural transportationMultilane highwaysHighway safetySafetyCrash injuriesData collectionGeorgiaGeorgia. Dept. of TransportationHunter, MichaelRodgers, MichaelGeorgia Tech Research CorporationGeorgia. Dept. of Transportation. Office of Materials & ResearchUnited States. Federal Highway AdministrationNTL-OPERATIONS AND TRAFFIC CONTROLS-OPERATIONS AND TRAFFIC CONTROLSNTL-OPERATIONS AND TRAFFIC CONTROLS-Traffic FlowNTL-SAFETY AND SECURITY-Highway SafetyUS Transportation CollectionThe primary objective of this study is the evaluation of the effectiveness of several proposed safetytreatments at two intersections in Habersham County, Georgia. The intersections selected for this study had highcrash rates leading to a Georgia Department of Transportation proposal for various safety improvements. Toevaluate the impact of the safety treatments, this study focused on an evaluation of various surrogate measuresof safety: speed, acceleration/deceleration rate, and Post Encroachment Time (PET). The study used videorecording as the primary data collection methodology and used custom software, developed as a part of theproject, for data reduction of the resulting videos. GPS probe vehicles were used to provide a ground truthreference. Data collected showed that the treatment had negligible impact on the behavior of the vehicles studiedregarding the surrogate measures considered.As a follow up study, the use of PET data as a surrogate measure was further explored. The objective of thisinvestigation was to determine the utility of using PET to rapidly determine the potential safety impact of atreatment. For this investigation data were collected at two pairs of intersections. Each pair was selected to be ofsimilar geometry and volumes but of different crash rates. For the given intersections PET demonstrated thepotential to distinguish between highly significant safety differences although it remains uncertain whatmagnitude of safety difference may be identified. Additional research will be needed before PET can be viewedas a robust quantitative surrogate measure for estimating intersection safety