I-85 NBL
I-85 NBL in 3.5 MI SE Of Duluth, Gwinnett County, Georgia received a condition grade of B (69/100). Built in 1958, the bridge carries 131K vehicles daily on I-85 NBL over Sweetwater Creek.
I-85 NBL carries a B on the BridgeSafety Condition Score with 69/100. Most component ratings are solid; one or two may show wear consistent with the structure’s age, but the bridge is not flagged as structurally deficient.
The bridge was built in 1958 and is now 68 years old, at or past the typical 50-year design life for bridges of its vintage. Maintenance and inspection cycles are correspondingly more involved than for newer structures. I-85 NBL carries an average daily traffic count of 131,000 vehicles, with 7 lane(s) crossing Sweetwater Creek. The owning agency is State Highway Agency; bridge inspection records flow into the federal NBI database annually.
Component Ratings
The riding surface, evaluated for cracking, spalling, and wear
Beams, girders, and trusses that support the deck
Piers, abutments, and foundations below the deck
Bridge Details
About This Bridge
I-85 NBL is a 68-year-old bridge located 3.5 MI SE Of Duluth in Gwinnett County, Georgia. The bridge carries I-85 NBL over Sweetwater Creek with 7 traffic lanes, handling approximately 131K vehicles per day. Built in 1958 and reconstructed in 2008, the structure spans 46.3 meters.
The bridge received a Condition Grade of B (69/100) based on Federal Highway Administration inspection data. Its deck is rated 7/9 (good), superstructure 7/9 (good), and substructure 7/9 (good).
This bridge is owned and maintained by State Highway Agency.
Location Map
Frequently Asked Questions
I-85 NBL has a Condition Score of 69/100 (Grade B). Its deck is rated 7/9, superstructure 7/9, and substructure 7/9 on the NBI scale. The bridge is not classified as structurally deficient.
I-85 NBL was built in 1958 and reconstructed in 2008, making it 68 years old. The average bridge age in the United States is 48 years.
I-85 NBL carries approximately 131K vehicles per day (average daily traffic). The bridge has 7 traffic lanes. It is 46.3 meters long and located on I-85 NBL in 3.5 MI SE Of Duluth, Gwinnett County, Georgia.
No, I-85 NBL is not classified as structurally deficient. All three primary components (deck, superstructure, and substructure) are rated above 4 on the 0-9 NBI scale.
I-85 NBL is located 3.5 MI SE Of Duluth in Gwinnett County, Georgia. The bridge carries I-85 NBL over Sweetwater Creek. Its coordinates are 33.962811, -84.104478. It is maintained by State Highway Agency.
I-85 NBL carries I-85 NBL over Sweetwater Creek. The bridge is 46.3 meters long and was built in 1958, with reconstruction in 2008.
Condition Score is calculated from deck (33%), superstructure (33%), and substructure (34%) NBI ratings with an age penalty for bridges over 50 years.
Source: FHWA National Bridge Inventory, 2026.