I-77
I-77 in 5.3 MI N Rock Hill, York County, South Carolina received a condition grade of B (69/100). Built in 1973, the bridge carries 125K vehicles daily on I-77 over Catawba River.
I-77 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 1973 and is now 53 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-77 carries an average daily traffic count of 124,700 vehicles, with 9 lane(s) crossing Catawba River. 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-77 is a 53-year-old bridge located 5.3 MI N Rock Hill in York County, South Carolina. The bridge carries I-77 over Catawba River with 9 traffic lanes, handling approximately 125K vehicles per day. Built in 1973 and reconstructed in 2000, the structure spans 327.7 meters.
The bridge received a Condition Grade of B (69/100) based on Federal Highway Administration inspection data. Its deck is rated 5/9 (fair), 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-77 has a Condition Score of 69/100 (Grade B). Its deck is rated 5/9, superstructure 7/9, and substructure 7/9 on the NBI scale. The bridge is not classified as structurally deficient.
I-77 was built in 1973 and reconstructed in 2000, making it 53 years old. The average bridge age in the United States is 48 years.
I-77 carries approximately 125K vehicles per day (average daily traffic). The bridge has 9 traffic lanes. It is 327.7 meters long and located on I-77 in 5.3 MI N Rock Hill, York County, South Carolina.
No, I-77 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-77 is located 5.3 MI N Rock Hill in York County, South Carolina. The bridge carries I-77 over Catawba River. Its coordinates are 34.987500, -80.983056. It is maintained by State Highway Agency.
I-77 carries I-77 over Catawba River. The bridge is 327.7 meters long and was built in 1973, with reconstruction in 2000.
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.