In a piece optimistically titled, “6 Places Where Cars, Bikes and Pedestrians All Share the Road as Equals,” the Atlantic’s CityLab blog puts Seattle on par par with cities in Sweden, Germany, and the Netherlands in our bike- and pedestrian-friendliness as one of the rarefied few places in the world where cars can coexist safely and peacefully alongside other roadway users.

Of course, the piece is talking about woonerfs—city streets, usually without traditional traffic-safety signifiers like lights, signs, and sharp curb cuts dividing “space from cars” from “space for people,” where cars, bikes, and pedestrians all use the same travel space. Woonerfs are popular lately because they are both fairly radical (for the U.S.) and relatively inexpensive solutions to car-pedestrian conflicts, limiting crashes by slowing everybody down to roughly the same speed.

But anyone who has witnessed Seattle’s downtown Bell Street Park (which my former colleague, Josh Feit, praised for “equalizing the infrastructure in downtown streets”) can tell you that it functions far differently from  true woonerfs in countries where “woonerf” is more than a trendy term for roads with benches.

On Bell Street, unsurprisingly, the experiment has been only a qualified success. Here, cars turn blithely onto a street clearly marked, at every intersection, with large “do not enter” signs, and drivers complain that the new road regime is just one more way for the city to rip off drivers with unfair traffic tickets. The presence of cars makes the street unpredictable for pedestrians, and the ill-defined boundaries of the so-called “park” (which may, at any moment, turn into a speedway for cut-through traffic) makes potential park uses such as food trucks and playgrounds dangerous or untenable.

I’m not knocking Seattle’s efforts (although it does seem like a few retractable bollards would fix the whole “Sorry-officer-I-didn’t-see-the-sign” problem, no?) Woonerfs are as routine in other countries as massive street-level parking lots are here, and it’s cool that Seattle is one of the first U.S. cities to really give them a go. But it will take a lot more experimentation—and a lot more half-functional woonerfs—for the city to convince drivers to share a public space with other users when they’ve spent so many decades considering it theirs.