Odd set of tiles go to...what?

[J C Lawrence]

From somewhere I got a small bag with the following track-tiles and I've
no idea what game they go to.

Yellow #5016, sharp curve city, $30, "SC"
Yellow #5018, sharp curve city, $20, "X"
Yellow #5019, broad curve city, $20, "X"

Green #20
Green #5000, three legs at 120 degrees and two stations, $30
Green #5001, three legs at $60 degrees and two stations, $30,
"X"

Brown #2071, same as a #43 except that one end has an
additional sharp curve making for three routes off one end of
the straight.

Any idea what game they're from/for? I assume they're a
supplement/update to something...

-- JCL