Me too. 54.5mph is my personal record. Now, I'll admit a lot of the cyclists in big cities are fools, been there done that, bought the t-shirt. But I have to posit those are the exception. I have been riding in Dallas for nearly 40 years, I know hundreds of people who ride a lot. We had a gal get run down on the Katy Trail a year ago. Knocked down and killed from the fall. I still wonder how fast the guy who hit her was going. That is a very congested trail.
Personally, I always do what I can to be a good citizen, I expect the peds with their iPods to turn right in front of me so I do what I can not to run over anybody. It ain't always easy but I have a pretty good record so far.
I've run across some of them, even the older, professional types, heading up the Mt. Lemmon highway. Riding three abreast, carrying on their conversation, oblivious to the cars piling up behind them. I'd look at the drivers, shrug my shoulders "I'm not with them! I'm not with them!" Educated, intelligent idiots, creating road rage.