LA 12 traverses an area of the state known as Acadiana and is also signed as the Acadiana Trail. The route connects the city of DeQuincy with US 171 and US 190, two of the region's main highways. It is also the only highway crossing the Texas–Louisiana border between US 190 to the north and the concurrent Interstate 10 (I-10) and US 90 to the south. LA 12 enters both Calcasieu Parish and Beauregard Parish twice along its route. This is due to a northern protrusion of the former from an otherwise linear border that encompasses the DeQuincy area.