Lionel bought the old K-Line name for the track, Super Streets.
Williams by Bachmann uses the name E-Z Streets.
As far as I know they should both fit with each other, not 100% sure on that though, as I have Super Streets and not E-Z Streets.
The only one that I know for sure that is being produced currently is Bachmann's E-Z Streets.
There could be a license agreement that won't let Lionel make the old K-Line Super Streets, but sell off old stock, again I am not 100% sure. The one thing is that license and legal problems had to be smoothed over with Sand Kan Holdings or somebody similar in China before Bachmann could sell the product as E-Z Streets.
Lee F.