The health benefits from riding bikes more than offset the dangers, especially when they're not forced to share lanes with road tanks piloted by people who don't take their driving responsibility seriously. Driving cars don't yield the same benefits. When you take that into account, driving is much more hazardous to your health.

Also, forcing cities to accommodate cars via zoning has lead to a huge host of problems, from making centers that are no longer walkable, and destroying the social fabric of the city that used to happen via face to face interactions. Anywhere there is fast traffic, people no longer want to walk, because it's incredibly stressful being near speeding cars.

If you want a visible demonstration of the difference, visit some small pre-car cities in Italy, the public places are wonderful, and you can see people bumping into each other and chatting all the time. People walk everywhere. Compare with the sprawling wastelands of asphalt we've created, including on some of the most expensive parking lots in the world in Silicon Valley.