The highway begins from LA 10 at Greensburg, and goes northeast once LA 432 turns east. As it goes eastward, it makes an intersection with LA 43, and LA 441 also intersects with the highway for a short time. As the highway enters Tangipahoa Parish, it intersects with Interstate 55 (I-55) in the city of Kentwood, has LA 1054 make an intersection with it, and then enters Washington Parish. Once there, LA 450 combines with the highway until it combines with a left-turning LA 1055, as LA 450 changes direction north where LA 38 was when it was combined. At Mount Hermon, LA 438 empties into the highway, while later on, LA 1055 turns east, leaving LA 38 southeast. As it intersects with LA 25, the highway ends at LA 430 near Bayou Chitto.