I had a poke around and there seems to be plenty of other traffic reports from places all over the world on Twitter.
Now when you are out and about traffic information like this, regularly updated, could be very handy. It would be a little hard to read on a PDA as you are driving along but none the less I think this is a great demonstration of where Twitter information does have benefits.
Interestingly, this sydneytraffic account is put together by someone not affiliated with the local authorities. I hope they at least take notice of things like this that could be of real benefit to people on the go.