The Louisiana Department of Transportation and Development says the closure of Highway 18 in Donaldsonville remains in effect and is expected to continue through December 19. This update follows an earlier DOTD notice that first announced the closure of the section near where the Mississippi River meets Bayou Lafourche, between Chetimatches Street and Iberville Street.
According to the previous DOTD announcement, the roadway was closed to allow crews to install steel pipes beneath the road surface. Because of this work, no traffic is permitted to pass through the affected section of Highway 18.
Motorists traveling through Donaldsonville are advised to follow posted detours:
- From Hwy. 18, take Hwy. 3089 to Hwy. 70, then Hwy. 3120 back to Hwy. 18.
- Alternatively, take Hwy. 18 to Hwy. 3120, then Hwy. 70 to Hwy. 3089, and return to Hwy. 18.
The project is part of infrastructure improvements along the Bayou Lafourche area and is expected to impact traffic in and around Donaldsonville until completion.
DOTD’s local announcements list show that the LA 18 closure in Ascension Parish remains marked as “extended” with no change to the closure period beyond the existing December 19 date. This extension was included in the latest parish-level DOTD announcements as of late December 2025.
For real-time conditions or potential last-minute changes, you can check the Louisiana DOTD 511 traveler information system which provides live traffic and closure updates.
Updated: January 14, 2026