Dr. Anne Lusk, a research associate at Harvard University's School of Public Health, argues that from a health-perspective, biking is more effective than walking. And the way to encourage biking, she says, is to make it safer:
"One of the reasons biking is so much safer in the Netherlands and Denmark is that the principal bicycle facilities in those two countries are cycle tracks - bike paths physically separated from motor vehicle traffic. Cycle tracks run parallel to the sidewalk, and are exclusively for bike riding. The 18,000 miles of cycle tracks in the Netherlands help to explain why 27 percent of Dutch trips are made on bicycles."
Thanks to Robert Steuteville