The signal from this system on 1.670 MHz is very strong here. A Shortwave (Midwave!) Listener in Austria heard it too. Check out the confirmation letter from the Virginia Department of Transportation. Nice of them to do this.
Here is the QSL letter sent to Austria:
They are running 10 watts into a 49 foot tall vertical with 40 radials. They have a text-to-speech system that is constantly describing weather conditions. Quite useful actually.
I found a web site that lists all the stations of this kind in the US:
I can see that the station I am hearing is just 2 miles from my location.
More information on this system: