ST 18 MAIN ST
Carrying ST 18 MAIN ST over ST 3
1.4 KM E BRAINTREE T.L., Norfolk, Massachusetts
Data updated May 2026
FHWA NBI record, refreshed with each annual release.
Bridge Snapshot: ST 18 MAIN ST
The ST 18 MAIN ST bridge in Norfolk, Massachusetts carries ST 18 MAIN ST over ST 3. It was built in 1957, making it 69 years old today. It was last reconstructed in 1980, extending its service life. The structure is built primarily of steel and spans 2 sections, stretching 43.9 meters (144 feet) end to end. Daily traffic averages 47,327 vehicles, placing it in the heavily-trafficked tier of Massachusetts bridges. It is owned and maintained by State Highway Agency.
The latest FHWA inspection records show a deck rating of 7/9, superstructure at 6/9, substructure at 6/9. The weakest component sits in fair condition. All reported major components score above the Poor range. Its NBI inventory load rating is 20.6 metric tons.
Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.
How ST 18 MAIN ST compares
Live comparison across Massachusetts.
Historical Sufficiency Rating
PlainBridge-computedFHWA discontinued this calculated item; it does not determine current condition, funding eligibility, posting, or closure. How the historical reference is calculated.
Condition Ratings
Full 0–9 scale + sufficiency-rating breakdown: how condition ratings work.
Structural Details
- Year Built
- 1957
- Last Reconstructed
- 1980
- Material
- Steel
- Number of Spans
- 2
- Structure Length
- 43.9 m (144 ft)
- Deck Width
- 27.2 m (89 ft)
- Owner
- State Highway Agency
- Avg Daily Traffic
- 47,327 vehicles/day
- Structure Number
- W32023348DOTNBI
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗Condition Analysis
- • At 7/9, the deck (driving surface) is in good shape and shows no significant wear.
- • At 6/9, the superstructure (beams and supports above the deck) shows fair condition, with minor wear flagged for upkeep.
- • The substructure (piers and abutments) is in fair condition (6/9), with minor deterioration that may require routine maintenance.
How to read this record
This page shows what the last federal inspection recorded, not whether ST 18 MAIN ST is safe to cross today. Here is how to use it.
- NBI condition ratings reflect the latest record in this annual dataset, not a live status. Current routine inspection intervals are risk-based.
- Learn how the 0–9 condition scale and Good/Fair/Poor categories are defined. How condition ratings work
- Compare ST 18 MAIN ST against other structures in Norfolk and across Massachusetts. Massachusetts bridges
- Noticed visible damage or a safety concern? Report it to the agency that owns the bridge, or call 911 in an emergency. How to report a bridge
Condition codes come straight from the FHWA National Bridge Inventory and are not a real-time safety judgment. Only the owning agency, a state DOT, county, or other owner, can post, restrict, or close a bridge.
Frequently Asked Questions
What do the condition ratings mean for ST 18 MAIN ST?
ST 18 MAIN ST in Norfolk, Massachusetts has a deck rating of 7/9, superstructure rating of 6/9, and substructure rating of 6/9 on the FHWA's 0–9 scale.
How often is ST 18 MAIN ST inspected?
ST 18 MAIN ST's responsible agency sets its routine interval under FHWA's risk-based inspection rules; this page does not expose the scheduled interval. It carries about 47,327 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. ST 18 MAIN ST is currently shown as Fair condition from its component ratings; that category is not a live closure or safety decision.
What is the inventory load rating for ST 18 MAIN ST?
ST 18 MAIN ST has an NBI inventory load rating of 20.6 metric tons.
Who is responsible for maintaining ST 18 MAIN ST?
ST 18 MAIN ST is owned and maintained by State Highway Agency.
How old is ST 18 MAIN ST and does age affect safety?
ST 18 MAIN ST was built in 1957, making it 69 years old and last reconstructed in 1980.
Disclaimer: Bridge condition data is from the FHWA NBI and reflects the last reported inspection. A Poor condition rating is not a live declaration that a bridge is closed or unsafe for travel. For current closure, posting, or safety information, contact the responsible transportation agency.
Every figure on PlainBridge is rendered directly from federal source data, no number is typed in by an editor. This page draws directly on federal source data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.