Illinois State Route 149 is the main east-west highway in the Southern Franklin County. IL St Rt 149 passes through the following towns in Franklin County. Royalton West Frankfort IL St Rt 149 is not multi-plexed in Franklin County. IL St Rt 149 intersects the following highways in Franklin County. Illinois State Route 184, near Royalton. Illinois State Route 148, near Zeigler. Interstate 57, near West Frankfort. Illinois State Route 37, at West Frankfort. Illinois State Route 34, near Thompsonville.