Good ground cover to plant in traffic circle?

I'm looking for a low maintenance, fast growing/spreading, plant to go in our block's traffic circle. The catch is that it needs to be able to withstand some occasional driving over, and on average not grow more than 15" tall. The height limit is city ordinance (Seattle), the driving is because the occasional lost delivery truck is forced to drive over the circle as it attempts to navigate our streets. Once in a while a kind neighbor will water the circle, but ideally it should be able to thrive without watering.

Suggestions?

Quick thought: yarrow. Varieties of yarrow are often used in lawn-alternative seed mixes. Durable, seems to survive dry spells well, spreads and provides lovely flowers for pollinators. It's even medicinal! Not sure how quickly it spreads though.

Wandering Jew. My sister planted some in So Cal, and never watered it. It took over every inch of bare soil under the oaks.
We parked our cars/trucks on it. You can't kill the stuff. It survived colder winters there than we get here in Seattle.

Full sun in a hot summer might slow it down, but that isn't a problem in Seattle.

Thanks for both suggestions. Of the two, the second sounds like it might take over more quickly, and I like the sound of that for a traffic circle that sits out in the middle of a street intersection. I don't know a lot about that particular plant... when I googled it to find the latin name, I discovered that there isn't full agreement around which plant is officially known as Wandering Jew and what the official latin name is. Tradescantia pallida, looks like one contender.

The Yarrow looks interesting too, might be something to consider as part of my yard, in the spots where I'd like to replace lawn with more of a wild flower meadow look.

Thanks!

Octavius

We've taken responsibility for our traffic circle. We failed to maintain it last summer w/occasional waterings. The only things that survived where lavender and a type of sedum, I think it's S. rupestre 'Angelina'. The sedum has definitely grown larger, but I wouldn't say it spread. We've got a lot of California Poppy that comes up annually that usually fills in the gaps.

I imagine other sedums would survive the neglect. However, fast might not be what they are. We've done a lot with other drought tolerant plants in our circle, but they might not like being run over.