http://www.greencar.com/articles/smart-car-offers-drivers-new-high-mpg-option-top-crash-rating.php
I’m surprised they did well in crash tests. Still, I wouldn’t want to drive one. I prefer SUVs or at least larger sedans. And as you said, not practical at all for families with kids.
Designed smarter, not bigger. Even the tires are part of the crash design (they're essentially rubber balloons, so what better to absorb crash energy?).