“Together we’re advancing initiatives focused on creating safer, more efficient travel options for all modes of transportation, from vehicles to bicycles to pedestrians,” Dave Ambuehl, the chief deputy district director of Caltrans, said in a news release.
https://www.sfgate.com/travel/article/new-intersection-project-first-kind-bay-area-19901199.php
As mentioned in the video, these are pretty hostile to pedestrians. Without knowing too much about the subject, I wouldn’t be surprised if roundabouts beat them handily - why else would countries with better road safety opt for roundabouts over diverging diamonds?