Track and Report Local Traffic on Twitter

I saw a cool post on Lifehacker today about traffic updates via Twitter.  A new service Commuter Feed is all set to help track traffic issues at several metropolitan areas via Twitter.
Here is how it works:

Follow @commuter on Twitter to get and receive the updates.

Then you can send updates on traffic in your area.  It does it by the local airport code.  So our area we would use IAD (Dulles) or DCA (National) or BWI (Baltimore).
Then to report on and accident or traffic you simply send a tweet to @commuter as follows

@commuter IAD Accident on Toll Road near Herndon

The only thing I see as a small issue, is trying to filter out your area versus all the updates people are sending to @commuter.  They have a web page specific to your area and you can subscribe to the RSS for that page, but as far as I could see there was not a way to only get the tweets for IAD.  Otherwise it seems like another great idea to use Twitter for.