4 Simple Steps To Request RRFB Approval (IA-21)

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Increasingly, rectangular rapid-flashing beacons (RRFBs) are becoming a go-to pedestrian crosswalk safety solution across the U.S. and beyond. Their popularity largely stems from the fact that, according to the FHWA, no other device without a red indication produces yield rates as consistently high.

If you’re just learning about this life-saving solution, you may not be familiar with the FHWA’s process for requesting RRFB Interim Approval (IA-21). Fortunately, everything you need to know is explained below.


A patent dispute at the end of 2017 led to the FHWA removing its previous RRFB Interim Approval, IA-11. This decision had nothing to do with the effectiveness of flashing light bars, which have been shown to increase driver compliance by as much as 90 percent.

The patent issue was laid to rest March 20, 2018. Shortly after this resolution, the FHWA issued Interim Approval 21 – Rectangular Rapid-Flashing Beacons at Crosswalks.

All state and local agencies must apply for new approvals under IA-21.

Interim Approval (IA-21) Updates

IA-21 requires newly installed RRFBs to utilize a WW+S (wig-wag plus simultaneous) flash pattern like all TAPCO RRFBs do. On existing installs, the previous flash pattern can remain in use until the next system maintenance cycle.

To reduce excessive nighttime glare, dimmable RRFB LEDs are also recommended for all new installations. For more information on the differences, click here.

How It Works

Step 1: Create a letter requesting IA-21 approval. Get started with our example letter.

Step 2: Copy the text from our example onto your agency letterhead and replace the sections in red with details pertaining to your community.

Step 3: Send your personalized approval letter to [email protected].

Step 4: While approval is pending, reach out to TAPCO to learn more about our RRFB pedestrian crosswalk solutions. Our 60+ years of experience make the selection, purchase and installation process easy, so you can focus on what you do best: improving safety and efficiency in your community.

Discover if RRFBs are the right solution for you.

Robert Kurka

TAPCO | Product Manager

With over a decade in business development, marketing and product management, Robert strives to improve transportation safety through innovation.

He is a pedestrian safety solutions expert who especially enjoys working with the TAPCO family to develop lifesaving products and solutions, such as the SafeWalk® Crosswalk Illuminator and the VizMark™ Pavement Marking Enhancement.

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