Originally Posted by
jon c.
I've never encountered such a signal in real life and wouldn't want to argue with traffic safety engineers, but it certainly seems like the flashing red phase would just add confusion. Especially with signage advising drivers they can proceed on flashing red. I don't really see the benefit of adding a new twist to the age old signal system that everyone understands.
Research over the past 15 years has made it clear that on roadways with 2 or more lanes in a/each direction and speeds greater than 35 mph, motor vehicle drivers just don't yield to pedestrians at midblock locations, even with enhanced crosswalk markings and a bunch of signs. The only devices that show significant driver yield rates are rectangular rapid-flash beacons (RRFB) or pedestrian hybrid beacons (PHB), and the PHB is considerably more effective in getting drivers to stop than RRFBs (although RRFBs are better than no active device at all).
The reason PHBs use a solid red interval followed by a flashing red interval is to bring all cross traffic to a full stop for the crossing user who activated the beacon, but then allow traffic to stop during the flashing red (flashing red is functionally and legally equivalent to a STOP sign), assess if there are people still crossing or entering the crosswalk, and if not, then proceed. Holding it solid red for that entire time would significantly impact traffic flow to the point where agencies would decide not to install a PHB.
There is research underway to see if standard red-yellow-green signals can be used effectively for midblock crosswalks. But past experience by some agencies was reported to not be as positive, which is why it's currently not encouraged by design guidelines.