From the west, LA 12 begins at the
Texas state line, midway across a
swing bridge over the
Sabine River. It continues the route of
Texas State Highway 12 (SH 12) from the
Newton County community of
Deweyville into
Calcasieu Parish, Louisiana. LA 12 heads east as an undivided two-lane highway through a largely uninhabited and heavily wooded area in the northwestern portion of the parish. After about , scattered residences appear as the highway approaches the small community of
Starks. Passing through the center of town, LA 12 intersects
LA 109, which connects with
Vinton to the south and
Merryville to the north. East of Starks, LA 12 curves northeast and runs parallel to the
Kansas City Southern Railway (KCS) tracks for the next . During this time, the highway briefly passes through a corner of
Beauregard Parish before crossing back into Calcasieu Parish. Shortly afterward, LA 12 passes the
DeQuincy Industrial Airpark, simultaneously entering the small city of
DeQuincy. It then curves slightly more to the northeast and away from the railroad line. After passing the local middle and high schools, the route curves due east into town on West 4th Street. LA 12 intersects
LA 389 (Cole Street) at the latter's southern terminus then makes a jog across the railroad tracks onto East 4th Street, entering the city's historic district. Signs direct visitors to the
DeQuincy Railroad Museum, located one block to the north at the convergence of two branches of the KCS Railway. Shortly after a second grade crossing, LA 12 intersects
LA 27, which heads northward along Page Street toward
DeRidder. Widening to accommodate a center turning lane, the two highways run east concurrently for two blocks until LA 27 turns south onto South Grand Avenue, heading toward
Sulphur.
Route classification and data LA 12 is classified by the
Louisiana Department of Transportation and Development (La DOTD) as a rural minor arterial. Daily traffic volume in 2013 averaged between 2,500 and 4,300 vehicles for most of the route. The highest figure reported was 7,500 vehicles through DeQuincy, and the lowest figure was 2,400 between Starks and DeQuincy. The posted speed limit is generally in rural areas, reduced to through DeQuincy. ==History==