In the early 1960s, US 90 was relocated from what is now LA 182 to its current route, known as the Evangeline Thruway, between Lafayette and Billeaud. In the late 1970s, LA 89 was extended along Southpark Road, an existing local road, providing a state-maintained connection with the new alignment of US 90. The remainder of LA 89 between Delcambre and Youngsville had been paved by the mid-1960s.
