Rapid Flashing Beacon Research shows Yielding Rates at 80%

In another note of research related to the Manual of Uniform Traffic Control Devices that is applicable to APBP members, the Texas Transportation Institute (TTI) recently completed research for the Federal Highway Administration focused on the yielding rates at Rectangular Rapid Flashing Beacons (RRFB). TTI has a nice summary page with a video that described the work completed. The research found that the overall average driver yielding was between 78 and 80 percent. I toured the TTI research labs in March 2013.

The yielding rate matches the experience in Portland through some research by PSU. In that work, the researchers found that the beacon was used by 82% of all pedestrians in the area (some didn't bother to push the button), and drivers yielded at a rate just over 90%. The study site included a crossing that included 35 MPH speeds (SW Barbur Blvd).

The earlier summary work done by TTI showed that in 22 sites in various locations yielding during the baseline period before the introduction of the RRFB ranged between zero and 26 percent. The introduction of the RRFB was associated with yielding that ranged between 72 and 96 percent at the 2-year follow-up.

Reesarch by TTI included studies on their test track in College Station, TX

If we're designing for safer crossings around a school or the overarching policy is to design for a community of people from 8 to 80 years old, is a yielding rate of 80% sufficient? 

The costs of a Rapid Flashing Beacon are approximately 35% of a full traffic signal and 50% of a pedestrian only signal or hybrid beacon. Do the cost savings of a RRFB outweigh the risks?