From the south, LA 31 begins at a junction with
LA 182 in
New Iberia. After a short distance, the route begins to travel along the west bank of
Bayou Teche. LA 31 crosses from
Iberia Parish into
St. Martin Parish near a junction with
LA 86. Passing through the historic town of
St. Martinville, LA 31 briefly overlaps
LA 96. Continuing northward, LA 31 makes a jog in the tiny community of
Parks and follows a western bend in Bayou Teche. In the town of
Breaux Bridge, LA 31 makes another jog and crosses
LA 94. At the north end of town, the highway crosses but does intersect
I-10, the main highway across southern Louisiana. Access to the interstate is instead provided by
LA 328 on the opposite bank of Bayou Teche. LA 31 continues to meander along several bends in the bayou, passing opposite
Cecilia en route to
Arnaudville. Here, the highway intersects the eastern terminus of
LA 93, connecting with nearby
I-49. Immediately afterward, LA 31 switches to the opposite bank of Bayou Teche and proceeds northwest to
Leonville, where it intersects
LA 103. A few miles later, LA 31 leaves the path of Bayou Teche and eventually comes to a T-intersection with
LA 742. The highway turns due west, enters the city limits of
Opelousas, and passes through a
diamond interchange with I-49. LA 31 proceeds on Creswell Lane a short distance further to its junction with LA 182 a few blocks south of the downtown area. ==Major intersections==