Dave Ripp. posted:It's very thin plastic Pete not routable.
As Dave said a superstreets section is very thin plastic. For the record, as closely as I can measure on my ruler graduated in 16ths of an inch, the thickness of the base under the rail groove is about halfway between 1/16th and 1/8th of an inch so let's call it 3/32nds of an inch.
HTH,
Bill