If you look at the wiki page where people add links to the instances of DIYtraffic that they've set up for their own area, you will see that the app is now running in Chicago, Fairfax VA, Portland OR, Rockville MD, San Francisco, and Washington DC.
Not bad, but can we go further? How many local instances of DIYtraffic can we get up and running today?
Instructions for installation are here: http://diycity.org/wiki/index.php?title=DIYtraffic_-_Instructions_for_In... and installation is a pretty quick and painless affair. Dan Greenblatt, who spearheaded the development effort, has also offered to configure our version of the app to run additional cities if anyone wants, so if you want a DIYtraffic in your town but don't have a server to put it on, write to him at dan dot greenblatt at gmail dot com and he'll do it for you.
If you do launch a DIYtraffic, be sure to 1) point back to this page explaining it, 2) tell people what it is in the bio area and 3) tweet about it to spread the word.
BTW, DIYtraffic works just fine for cities outside of the U.S., if you give it an RSS feed for local traffic updates. The feed we're currently using, from Yahoo, is only for the U.S. unfortunately (why is that??).