This is common in a lot of Seattle neighborhoods, but the custom doesn’t extend beyond the city limits. For the most part it just works, but when I’m in a car with someone not from the city I always need to inform the driver or they just expect right of way. I lived near one of these intersections and personally witnessed two collisions over ten years. Neither were serious. I think these intersections largely work as a custom, save for the people not already accustomed.