Evaluation of Rural Intersection Treatments

2018PDFTech ReportIHRB Project TR-695DTRT13-G-UTC37Human factors in accidentsDriver errorsIntersectionsRural highwaysdriver behaviorpost-mounted stop sign beaconsrural intersection safetystop-controlled intersectionsstopping behaviorsurrogate safety measuresIowaIowa State University. Center for Transportation Research and EducationHallmark, ShaunaJames, JevanKnickerbocker, SkylarHawkins, NealThapa, RajuLitteral, TheresaIowa State University. Institute for TransportationIowa. Highway Research BoardMidwest Transportation CenterIowa. Dept. of TransportationUnited States. Dept. of Transportation. Office of the Assistant Secretary for Research and TechnologyNTL-SAFETY AND SECURITY-AccidentsNTL-OPERATIONS AND TRAFFIC CONTROLS-OPERATIONS AND TRAFFIC CONTROLSUS Transportation CollectionShauna Hallmark (orcid.org/0000-0001-5187-8022); Jevan James (orcid.org/0000-0003-1198-4909); Skylar Knickerbocker (orcid.org/0000-0002-0202-5872); Neal Hawkins (orcid.org/0000-0003-0618-6275); Raju Thapa (orcid.org/0000-0002-1930-0535); and Theresa Litteral (orcid.org/0000-0003-4978-6430); Because crashes at rural intersections frequently result from failure to yield, agencies attempt to find countermeasures that encourage drivers to stop and yield appropriately. In this research, two promising low-cost rural intersection countermeasures were selected and evaluated for their impact on safety: post-mounted beacons and retroreflective strips on stop sign posts. The post-mounted beacons were set to activate only when an approaching vehicle\u2019s speed surpassed a predetermined threshold. High-crash rural stop-controlled intersections were identified using in-house crash and roadway data and then filtered for suitability via site visits. The retroreflective strips were installed on stop signs at 14 intersections on both minor street approaches. The post-mounted beacons were installed on stop signs at 10 approaches at 6 intersections. Driver behavior was used to assess the countermeasures. Because the post-mounted beacon was expected to noticeably impact driver behavior while the retroreflective strips were not, driver behavior data were only collected at locations where post-mounted beacons were installed. Video data were collected using trailer-mounted cameras at all 10 approaches where post-mounted beacons were installed 1 month before and 1 month after installation. For 6 of the 10 approaches, data were also collected 12 months after installation. Several driver behavior metrics, including type of stop, stopping position, braking point, and number of times braking, were reduced for a random sample of vehicles for each approach in each evaluation period and were compared before and after installation