[0xfeba]

Cars today are also far, far safer than 20 (ok, 40) years ago. But speed limits have increased, and fatalities per mile driven have decreased.

The point of the article was that speed limits should be set to keep the most amount of people at the same speed. Otherwise by reducing them too much, you create environments where there are greater differences in speed between cars. That is what is dangerous, not the actual number itself.

[ihattendorf]

Higher speed is absolutely more dangerous than slower. Yes speed differences are dangerous as well, but hitting a wall at 40 mph is a lot better than at 80. Higher speeds are also much more dangerous for pedestrians and cyclists, someone posted the numbers in another comment.