I-75 (NBL)
I-75 (NBL) in 4.9 MI SE Of Marietta, Cobb County, Georgia received a condition grade of B (72/100). Built in 1965, the bridge carries 325K vehicles daily on I-75 (NBL) over M-9495 Terrell Mill RD.
I-75 (NBL) carries a B on the BridgeSafety Condition Score with 72/100. 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 1965 and is now 61 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-75 (NBL) carries an average daily traffic count of 325,000 vehicles, with 8 lane(s) crossing M-9495 Terrell Mill RD. 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-75 (NBL) is a 61-year-old bridge located 4.9 MI SE Of Marietta in Cobb County, Georgia. The bridge carries I-75 (NBL) over M-9495 Terrell Mill RD with 8 traffic lanes, handling approximately 325K vehicles per day. Built in 1965 and reconstructed in 1990, the structure spans 40.2 meters.
The bridge received a Condition Grade of B (72/100) 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-75 (NBL) has a Condition Score of 72/100 (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-75 (NBL) was built in 1965 and reconstructed in 1990, making it 61 years old. The average bridge age in the United States is 48 years.
I-75 (NBL) carries approximately 325K vehicles per day (average daily traffic). The bridge has 8 traffic lanes. It is 40.2 meters long and located on I-75 (NBL) in 4.9 MI SE Of Marietta, Cobb County, Georgia.
No, I-75 (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-75 (NBL) is located 4.9 MI SE Of Marietta in Cobb County, Georgia. The bridge carries I-75 (NBL) over M-9495 Terrell Mill RD. Its coordinates are 33.911942, -84.478858. It is maintained by State Highway Agency.
I-75 (NBL) carries I-75 (NBL) over M-9495 Terrell Mill RD. The bridge is 40.2 meters long and was built in 1965, with reconstruction in 1990.
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.