FHWA NBI 2024 Inspection record Public-domain dataset

ST177 AMER LGN HWY

Carrying ST177 AMER LGN HWY over WATER E BR WESTPORT RIV

.3 MI SW OF US 6, Bristol, Massachusetts

Data updated May 2026

FHWA NBI record, refreshed with each annual release.

Fair
24 t Inventory load rating

Bridge Snapshot: ST177 AMER LGN HWY

The ST177 AMER LGN HWY bridge in Bristol, Massachusetts carries ST177 AMER LGN HWY over WATER E BR WESTPORT RIV. It was built in 1941, making it 85 years old today. The structure is built primarily of steel and spans 1 section, stretching 18.3 meters (60 feet) end to end. Daily traffic averages 10,345 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 6/9, superstructure at 7/9, substructure at 7/9. The weakest component sits in fair condition. All reported major components score above the Poor range. Its NBI inventory load rating is 23.6 metric tons.

Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.

How ST177 AMER LGN HWY compares

▼ 17.6
Load rating vs Massachusetts average (41.2 t)
Bottom 10%
Lower load rating than 90% of Massachusetts bridges
384
Bridges in Bristol · 23 in Poor condition
ST177 AMER LGN HWY 23.6 t
Massachusetts average 41.2 t

Live comparison across Massachusetts.

Historical Sufficiency Rating

PlainBridge-computed
84.8 / 100 - historical 80–100 band
Structural adequacy /55
46.5
Serviceability /30
28.0
Essentiality /15
13.3
Special reductions
−3.0

FHWA discontinued this calculated item; it does not determine current condition, funding eligibility, posting, or closure. How the historical reference is calculated.

Condition Ratings

Deck
6/9
Fair (5–6)
Superstructure
7/9
Good (7–9)
Substructure
7/9
Good (7–9)
Inventory Load Rating
23.6 t
NBI inventory level (metric tons)
Overall Condition
Fair

Full 0–9 scale + sufficiency-rating breakdown: how condition ratings work.

Structural Details

Year Built
1941
Material
Steel
Number of Spans
1
Structure Length
18.3 m (60 ft)
Deck Width
13.6 m (45 ft)
Owner
State Highway Agency
Avg Daily Traffic
10,345 vehicles/day
Structure Number
W300143W4DOTNBI

Condition Analysis

  • The deck (driving surface) is in fair condition (6/9), with minor deterioration that may require routine maintenance.
  • The superstructure (beams and supports above the deck) is in good condition (7/9), showing no significant deterioration.
  • At 7/9, the substructure (piers and abutments) is in good shape and shows no significant wear.

How to read this record

This page shows what the last federal inspection recorded, not whether ST177 AMER LGN HWY 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 ST177 AMER LGN HWY against other structures in Bristol 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 ST177 AMER LGN HWY?

ST177 AMER LGN HWY in Bristol, Massachusetts has a deck rating of 6/9, superstructure rating of 7/9, and substructure rating of 7/9 on the FHWA's 0–9 scale.

How often is ST177 AMER LGN HWY inspected?

ST177 AMER LGN HWY'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 10,345 vehicles per day.

What does “structurally deficient” mean in older bridge reports?

FHWA retired that reported status beginning with the 2018 archive. ST177 AMER LGN HWY 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 ST177 AMER LGN HWY?

ST177 AMER LGN HWY has an NBI inventory load rating of 23.6 metric tons.

Who is responsible for maintaining ST177 AMER LGN HWY?

ST177 AMER LGN HWY is owned and maintained by State Highway Agency.

How old is ST177 AMER LGN HWY and does age affect safety?

ST177 AMER LGN HWY was built in 1941, making it 85 years old.

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.

Data sourced from the Federal Highway Administration National Bridge Inventory. See our methodology for details. Retrieved and formatted by PlainBridges

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.