I 93 /US1/ST3
I 93 /US1/ST3 in 4.4 MI S Of JCT I90&I93, Suffolk County, Massachusetts received a condition grade of C (49/100). Built in 1955, the bridge carries 173K vehicles daily on I 93 /US1/ST3 over HWY Nep Av/Galv/Mrsy.
I 93 /US1/ST3 carries a C on the BridgeSafety Condition Score with 49/100. Component ratings sit in the middle of the FHWA NBI distribution; rehabilitation programming is likely on the owning agency’s medium-term horizon.
The bridge was built in 1955 and is now 71 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 93 /US1/ST3 carries an average daily traffic count of 173,365 vehicles, with 8 lane(s) crossing HWY Nep Av/Galv/Mrsy. 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 93 /US1/ST3 is a 71-year-old bridge located 4.4 MI S Of JCT I90&I93 in Suffolk County, Massachusetts. The bridge carries I 93 /US1/ST3 over HWY Nep Av/Galv/Mrsy with 8 traffic lanes, handling approximately 173K vehicles per day. Built in 1955 and reconstructed in 1984, the structure spans 364.8 meters.
The bridge received a Condition Grade of C (49/100) based on Federal Highway Administration inspection data. Its deck is rated 6/9 (fair), superstructure 5/9 (fair), and substructure 5/9 (fair).
This bridge is owned and maintained by State Highway Agency.
Location Map
Frequently Asked Questions
I 93 /US1/ST3 has a Condition Score of 49/100 (Grade C). Its deck is rated 6/9, superstructure 5/9, and substructure 5/9 on the NBI scale. The bridge is not classified as structurally deficient.
I 93 /US1/ST3 was built in 1955 and reconstructed in 1984, making it 71 years old. The average bridge age in the United States is 48 years.
I 93 /US1/ST3 carries approximately 173K vehicles per day (average daily traffic). The bridge has 8 traffic lanes. It is 364.8 meters long and located on I 93 /US1/ST3 in 4.4 MI S Of JCT I90&I93, Suffolk County, Massachusetts.
No, I 93 /US1/ST3 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 93 /US1/ST3 is located 4.4 MI S Of JCT I90&I93 in Suffolk County, Massachusetts. The bridge carries I 93 /US1/ST3 over HWY Nep Av/Galv/Mrsy. Its coordinates are 42.285769, -71.042917. It is maintained by State Highway Agency.
I 93 /US1/ST3 carries I 93 /US1/ST3 over HWY Nep Av/Galv/Mrsy. The bridge is 364.8 meters long and was built in 1955, with reconstruction in 1984.
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.