While Rectangular Rapid Flashing Beacons (RRFB) are currently in interim approval, some cities are now experimenting with Circular Rapid Flashing Beacons (CRFB) to see if they are more effective than RRFBs.
Does anyone know of any data that has been collected by different cities determining RRFBs vs. CRFBs? Perhaps if CFRBs are determined to be more effective than RRFBs the FHWA may rescind the interim approval for the RRFB and introduce a new interim approval for the CRFB.
I don't expect the FHWA to rescind approval for either under any circumstance. If anything, both would become options, with the state deciding their own preference based on their own studies.
I'd hazard a guess that the rapid circular flashing beacons are just agencies using circular LED beacons with the flash pattern of the RRFBs.
Quote from: jakeroot on May 05, 2015, 12:30:30 AM
I don't expect the FHWA to rescind approval for either under any circumstance. If anything, both would become options, with the state deciding their own preference based on their own studies.
CRFBs are not yet even in interim approval, they are still considered experiments by the FHWA.
Quote from: Pink Jazz on May 05, 2015, 11:50:39 AM
Quote from: jakeroot on May 05, 2015, 12:30:30 AM
I don't expect the FHWA to rescind approval for either under any circumstance. If anything, both would become options, with the state deciding their own preference based on their own studies.
CRFBs are not yet even in interim approval, they are still considered experiments by the FHWA.
I thought about that after I posted my comment. What I meant to say was, should the CRFB be introduced into the MUTCD, I wouldn't expect it to replace the RRFB. They would both become options.
If by circular you mean the sign is bordered with LED's, then the circular beats the rectangular completely for visibility. We have examples of each in Coos Bay OR and the lights all around the sign stand out much better.
Rick
Quote from: nexus73 on May 05, 2015, 06:31:24 PM
If by circular you mean the sign is bordered with LED's, then the circular beats the rectangular completely for visibility. We have examples of each in Coos Bay OR and the lights all around the sign stand out much better.
Rick
I think he means these:
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fwww.flagstaff.az.gov%2Fimages%2Fpages%2FN2923%2FCRFB.JPG&hash=64c091c3d9d39bb7b2b08238bb16a5b802ec4e86)
Quote from: jakeroot on May 05, 2015, 06:34:58 PM
Quote from: nexus73 on May 05, 2015, 06:31:24 PM
If by circular you mean the sign is bordered with LED's, then the circular beats the rectangular completely for visibility. We have examples of each in Coos Bay OR and the lights all around the sign stand out much better.
Rick
I think he means these:
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fwww.flagstaff.az.gov%2Fimages%2Fpages%2FN2923%2FCRFB.JPG&hash=64c091c3d9d39bb7b2b08238bb16a5b802ec4e86)
Instinctive reaction: It's a RR Crossing.
No images for what a "circular" truly is showed up when I used the search engine. Guess we'll have to wait for someone who has the official version to show up and let us know what the term actually means. I know what I saw in Coos Bay and the surrounded edge stood out better than a rectangular or old-fashioned dual lights setup.
Rick
Quote from: nexus73 on May 05, 2015, 06:31:24 PM
If by circular you mean the sign is bordered with LED's, then the circular beats the rectangular completely for visibility. We have examples of each in Coos Bay OR and the lights all around the sign stand out much better.
LEDs in the border or legend/symbol on a sign can be used to enhance conspicuity of the sign or sign message. This is an allowable use in the 2009 MUTCD and is not under an interim approval (as RRFBs are).
LEDs are considered part of the sign, even if they flash. This is completely separate from a beacon, which is a device that emits nothing but light with no sign elements. Beacons and LEDs in a sign are both prescribed to flash at the same rate of 50-60 times per minute (compare this to RRFBs, which have a flash period of 70-80 times per minute).