Kentucky State Route 212 is a short multi-lane highway connecting the Cincinnati-Northern Kentucky International Airport to Interstate 275. KY St Rt 212 passes through the following town in Boone County. Burlington KY St Rt 212 is not multi-plexed in Boone County. KY St Rt 212 intersects the following highways in Boone County. Kentucky State Route 20, near Constance. Interstate 275, at Burlington. Kentucky State Route 236, at Burlington.