Detail for Crossings on Curves This Blair Line N Scale Curved Wood Grade Crossing is ready to install on your highway and road crossings. Similar to those found all over North America, laser-cut wood kits are detailed with laser-etched boards and bolt holes. Curved Wood Grade Crossings are available in a variety of radii to fit common curved track. N Scale curved crossings will fit curves plus or minus 1′ of listed radius. See the entire line of Blair Line N Scale wood grade crossings.