01508nam 2200409 a 450 991070021630332120120716124954.0(CKB)5470000002408817(OCoLC)799882756(EXLCZ)99547000000240881720120716d2009 ua 0engurmn|||||||||txtrdacontentcrdamediacrrdacarrierRectangular rapid flash beacon (RRFB)[electronic resource][Washington, D.C.] :U.S. Dept. of Transportation, Federal Highway Administration,[2009]1 online resource (2 unnumbered pages) color illustrationsTitle from title screen (viewed on July 16, 2012)."May 2009.""FHWA-SA-09-009."Includes bibliographical references.Rectangular rapid flash beacon RoadsUnited StatesInterchanges and intersectionsSafety measuresTraffic signs and signalsUnited StatesPedestrian crosswalksUnited StatesSafety measuresRoadsInterchanges and intersectionsSafety measures.Traffic signs and signalsPedestrian crosswalksSafety measures.United States.Federal Highway Administration.GPOGPOBOOK9910700216303321Rectangular rapid flash beacon (RRFB)3153126UNINA