Experiment on a sheet of Foam
Three tracks: A, B and C; with 13" curves (C is 13.5", but who's counting?) A is cork held down by foam tack, with 1/2" temporary pins. B is cork held down by Liquid Nails, with 2" temporary pins. C is AMI Instant Roadboard, no glue between roadbed and foam, both Foam Tack and Liquid Nails between track and roadbed. no pins.