I had read that previously and just re-read it, I don't think the blurb on the Wiki is very definitive one way or the other. I agree the speed limits aren't as low as they could be, but seeing as these streets allow pedestrians to walk throughout the right of way and motor vehicles must yield to them, this is effectively achieving the same goal. My experience living a block from a Healthy Street is that there is much less traffic on them and more pedestrians and cyclists.