Perhaps a new role for urban trees
I criticize "roundabouts" as a suburban treatment more focused on facilitating motor vehicle movement rather than balancing the competing needs of pedestrians and bicyclists with vehicle.
But roundabouts can be seen as a souped up version of a "diverter" that is designed to impede traffic flow in some manner.
I remember various intersection in Seattle specifically -- that are a kind of hindrance technique in the middle of an intersection, designed to slow traffic down and to force deviation from driving in a straight line.
Except for the "safety" reason, why not utilize trees as well?
It's been a few years since I've been to Seattle, and according to this Streetsblog post, "Seattle’s Playful Traffic Circles Tame Neighborhood Streets," trees are part of the program now.
Probably inspired by the City Repair program in Portland, sometimes city transportation departments allow special painting treatments in intersections.
This one in Somerville, Massachusetts, by Liz LaManche of Earthsign Studio, uses the garden path as a motif.