Evaluation of IdaShield sign safety benefits at highway-rail crossing in Idaho.

PDFTech ReportFHWA-ID-14-223RP 223Railroad grade crossingsTraffic signsBefore and after studiesAccident dataSurveysCountermeasuresDriving simulatorsRailroad safetyHighway safetyIdahoIdaho. Transportation Dept.Dixon, Michael P.Dyre, BrianWulfhorst, J.D.Abdel-Rahim, AhmedGrover, AlexMeyer, MarkReyna, Monica A.Foltz, Barbara E.University of Idaho. Dept. of Civil EngineeringUnited States. Federal Highway AdministrationUS Transportation CollectionThis report describes findings from a study aimed at assessing the safety impact of IdaShield signs installed at 1,341 highwayrailroad crossings in Idaho. Specifically, our research assessed the marker\ue2\u20ac\u2122s effectiveness using three measures:\ue2\u20ac\ua2 Before-and-after analysis of historical crash data preceding and following installation of the IdaShield marker.\ue2\u20ac\ua2 User assessment survey measuring user understanding of the IdaShield and changes in user response due to theIdaShield.\ue2\u20ac\ua2 Simulated driving test environment that exposed participants to various controlled circumstances related tohighway railroad crossings.The before-and-after analysis of test data showed crashes were significantly decreased by 38.6 percent after the IdaShieldinstallation and these effects were largely attributed to the IdaShield. The user assessment survey found users understood thepurpose of the IdaShield, believed it enhanced intersection visibility, and would improve safety. Finally, the driver simulationshowed how the IdaShield changed driver responses at highway railroad crossings, but only for conditions in which it was pairedwith a YIELD sign and a train was approaching. No significant safety benefit was noted when the IdaShield sign was paired with aSTOP sign. Because the IdaShield produces positive overall outcomes on driver safety and does not have any apparent negativeeffects, we recommend the signage should continue to be required to increase visibility and safety at passive at-grade railwaycrossings in Idaho where a STOP sign is not present