I 93 NB
I 93 NB in 0.1 MI Sly Andover T.L., Middlesex County, Massachusetts received a condition grade of C (50/100). Built in 1958, the bridge carries 146K vehicles daily on I 93 NB over HWY Vale ST.
I 93 NB carries a C on the BridgeSafety Condition Score with 50/100. 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 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 93 NB carries an average daily traffic count of 145,580 vehicles, with 3 lane(s) crossing HWY Vale ST. 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 NB is a 68-year-old bridge located 0.1 MI Sly Andover T.L. in Middlesex County, Massachusetts. The bridge carries I 93 NB over HWY Vale ST with 3 traffic lanes, handling approximately 146K vehicles per day. Built in 1958 and reconstructed in 1975, the structure spans 13.7 meters.
The bridge received a Condition Grade of C (50/100) based on Federal Highway Administration inspection data. Its deck is rated 5/9 (fair), superstructure 6/9 (fair), and substructure 5/9 (fair).
This bridge is owned and maintained by State Highway Agency.
Location Map
Frequently Asked Questions
I 93 NB has a Condition Score of 50/100 (Grade C). Its deck is rated 5/9, superstructure 6/9, and substructure 5/9 on the NBI scale. The bridge is not classified as structurally deficient.
I 93 NB was built in 1958 and reconstructed in 1975, making it 68 years old. The average bridge age in the United States is 48 years.
I 93 NB carries approximately 146K vehicles per day (average daily traffic). The bridge has 3 traffic lanes. It is 13.7 meters long and located on I 93 NB in 0.1 MI Sly Andover T.L., Middlesex County, Massachusetts.
No, I 93 NB 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 NB is located 0.1 MI Sly Andover T.L. in Middlesex County, Massachusetts. The bridge carries I 93 NB over HWY Vale ST. Its coordinates are 42.617011, -71.175397. It is maintained by State Highway Agency.
I 93 NB carries I 93 NB over HWY Vale ST. The bridge is 13.7 meters long and was built in 1958, with reconstruction in 1975.
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.