Since the 1955 renumbering, the route of LA 9 has remained virtually the same. Most of the minor changes have resulted from the smoothing of several curves over the years, often as part of repaving projects. A modest curve east of Bryceland was straightened sometime before 1967. A number of curves between Arcadia and Athens were straightened during the 1970s. Pieces of the original roadbed survive as local roads looping off of the current alignment. A short section of highway hugging the Louisiana and North West Railroad line at Mulnix was re-routed around the same time. The original alignment there followed what is now Dansby Road. The most recent improvements have occurred in Natchitoches Parish. A sharp curve at a defunct crossing of the Kansas City Southern Railway was smoothed out in 2010. In November of that year, a new bridge over Black Lake was opened, replacing a lower span that was prone to flooding.