February 1


FHWA Terminates Interim Approval of Rectangular Rapid-Flashing Beacons

By Mike Spack

February 1, 2018

FWHA, Rectangular Rapid Flashing Beacons, RRFB

By Bryant Ficek, PE, PTOE

For those who haven’t heard yet, the Federal Highway Administration (FHWA) recently repealed their Rectangular Rapid Flashing Beacons (RRFB) interim approval on December 21, 2017. RRFBs supplement standard pedestrian and school crossing warning signs across uncontrolled approaches. Rather than the MUTCD standard of a circular light flashing once per second, the RRFB uses a rectangular shape with high-intensity LED lights, flashing in wig-wag “flickering” flash pattern. The lights are also mounted immediately between the crossing sign and the sign’s supplemental arrow plaque. Since the RRFB design did not comply with the MUTCD, the interim approval was necessary.

With the interim approval terminated, agencies are no longer in compliance with the MUTCD if they install these devices and risk increased liability. Per the FHWA termination memo, RRFBs already installed may continue to operate until the end of their useful service life. No new or replacement RRFBs are allowed. The FHWA has a FAQ page on the termination here.

As we understand, the issue is a patent claim on the RRFB. Patented traffic control devices are not allowed in the MUTCD as they run counter to the principle of uniformity and consistency in communication to road users. Patents also violate the Federal government general prohibition against endorsing or appearing to endorse a specific product, company, or individual.

So what does this all mean? At the moment, it means revisiting other available devices to assist with pedestrian crossings, such as:

  • Regulatory (black and white signs) signs informing drivers of the legal requirement to stop
  • Overhead pedestrian crossing signs
  • In-street pedestrian crossing signs
  • Pedestrian-activated Flashing LEDs in the warning sign border
  • Pedestrian-activated warning beacons
  • In-roadway warning lights
  • Midblock Pedestrian Signals
  • Pedestrian Hybrid Beacons

In addition, consider geometric to improve pedestrian crossing safety.

Although we have these other methods, there’s no doubt we have lost a great tool. From the research we have seen, RRFBs were quite effective in getting drivers’ attention and slowing/stopping for pedestrians.

Beyond that, there’s lots of gray area. A long discussion is occurring through the Institute of Transportation Engineers’ (ITE) Community Forum. Not being a patent lawyer or even playing one on TV, here’s a summary of some of the issues beign discussed:

  • Can agencies continue with RRFBs in the pipeline for construction or purchased for future use?
  • What’s the liability for an agency if a crash occurs at an existing RRFB, or occurs at a location with an RRFB removed or not installed due its terminated interim approval?
  • What’s the risk to an agency of an RRFB installation versus the non-installation of an effective and proven safety device?
  • Can the FHWA or ITE create a unique solution, similar to the RRFB, but different enough so it does not run afoul of the patent?
  • Will the FHWA withhold federal transportation funding from agencies if they continue to install RRFBs for not being in compliance with the MUTCD?

We have more questions than answers at this point. Hopefully, more guidance or clarifications from the FHWA will help us get back to improving safety for all users, with or without the RRFB.

What are your thoughts on the FHWA decision to Terminate Interim Approval of Rectangular Rapid-Flashing Beacons? Leave a comment below. I would love to hear your thoughts.


Bryant Ficke Bio

  • In response to your bullets,
    – Recent update, “FHWA believes it is in the public interest…to complete projects that have documentation of RRFBs with procurements issued and/or construction plans underway prior to FHWA’s December 21, 2017 notice.”
    – for an existing installation with documentation of interim approval, those RRFBs may remain in place for the duration of their useful life. Since explicit permission is given to leave them in place, and there’s no documented safety concern, I don’t see any liability in leaving them up despite the termination of interim approval.
    – Risk to an *agency* of new RRFBs vs. non-installation – the agency would be at risk for installing a non-approved device. No device would be the safer bet for the agency, since the MUTCD does not require devices to be used in most situations, but does regulate the type and application of devices. Risk to a *pedestrian*? Peds are better off with the RRFBs than no device or flashing round beacon, according to the study that led to interim approval. This leads agencies to decide if potential lawsuits or pedestrian safety takes precedence.
    – Hopefully someone comes up with an alternative solution quickly. Some have suggested that a slightly different flash pattern could be as effective.
    – Technically, they could withhold funds, just as they could for any agency that doesn’t have a sign inventory in place or uses purple street name signs, but I’ve not seen that happen.

  • Hi Bryant:

    Thanks for the info. could you also discuss other acceptable pedestrian crossing aids other than the RRFB and show a photo of each of them. Thank you so much!


  • For those looking for RRFB alternatives, check out the FHWA Safe Transportation for Every Pedestrian (STEP) website. It has plenty of resources and ideas for non-RRFB treatments.

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    Mike Spack

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