The next painted intersection we're visiting is Piazza di Wilbur, at N. Holman St. & Wilbur Ave. This one was created in 2012, sponsored by the Overlook neighborhood association. This was around the same time Overlook Feng Shui went in at the N. Concord/Failing/Melrose/Overlook intersection. A May 2012 Oregonian article mentions both intersections, and includes a short video clip about Piazza di Wilbur.
Elsewhere on the interwebs, I found what seems to be a project website, though it's private and members-only, for whatever reason. The piazza is also listed on "World-Wide Labyrinth Locator", thanks to the little maze in the middle. And someone's Prezi presentation about City Repair intersections describes the design as "some kind of vortex". Cryptic private website, mysterious maze/vortex in the middle of an intersection, suspiciously foreign-sounding name... Obviously there's some sort of fnord intricate conspiracy going on. Aliens and bigfoot and fluoride are almost certainly involved, if you ask me.