I was thinking of posting this in the A&S section, but why start yet another flame war? I am reading the recent book "Traffic" by Tom Vanderbilt, and find that it has a lot of info in it that cyclists would find interesting. Cyclists are mentioned specifically in a number of places, and in other places the things he points out are applicable to cycles as well as cars.
The book goes into the psychology, physiology, etc. of roads and traffic conditions, and tries to explain a number of seeming contradictions, such as why the most dangerous roads may actually be the safest (the safer they make a road, the faster people tend to drive on it, and have more accidents).
Anyway, there are more interesting examples and anecdotes than I could number here. It's a fairly fast read and highly recommended for anyone that uses the public roads: cars, cyclists, or even pedestrians (as in more people get hit in legal crosswalks than when jaywalking, because jaywalkers pay closer attention to the traffic).