BLACK ROCK RD
Carrying BLACK ROCK RD over GREAT SENECA CREEK
0.7 MI N OF JCT SR 28, Montgomery, Maryland
Inventory: FHWA NBI 2024 · last ETL August 2026
FHWA NBI record, refreshed with each annual release.
BLACK ROCK RD in Montgomery, Maryland is rated Fair in the FHWA's 2024 National Bridge Inventory.
Built in 1965, it carries 3 rated components on the inspecting agency's 0-9 scale, and its weakest reported component scores 5. The lowest applicable rating sets the federal condition category, so this Fair result describes the weakest reported component rather than the structure as a whole. No NBI category is a closure decision or a live crossing-safety verdict.
NBI record plate
Structure MD:200000M-0047010
INTERSTATE-ERA · STEEL · MULTI-SPAN · TIED-CTRL · LOCAL-ADT · HEAVY-LOAD · CAT-FAIR
- INTERSTATE-ERA 1950–1979
- STEEL Steel
- MULTI-SPAN 2 spans
- TIED-CTRL Tied control
- LOCAL-ADT Local ADT
- HEAVY-LOAD Heavy load
- CAT-FAIR Fair
Inspection-sheet codes from this record’s year, material family, spans, controlling component, ADT, inventory load, and NBI category, not a live closure verdict.
Bridge Snapshot: BLACK ROCK RD
The BLACK ROCK RD bridge in Montgomery, Maryland carries BLACK ROCK RD over GREAT SENECA CREEK. It was built in 1965, making it 61 years old today. It was last reconstructed in 1993, extending its service life. The structure is built primarily of steel and spans 2 sections, stretching 22.6 meters (74 feet) end to end. Daily traffic averages 373 vehicles, placing it in the lower-traffic tier of Maryland bridges. It is owned and maintained by County Highway Agency.
The latest FHWA inspection records show a deck rating of 6/9, superstructure at 5/9, substructure at 5/9. The weakest component sits in fair condition. All reported major components score above the Poor range.
How BLACK ROCK RD compares
Age against the county: built in 1965, earlier than 330 of Montgomery's 515 bridges with a recorded construction year (64%), against a county median build year of 1982. Age is not a defect on its own, but it is the population from which future Poor ratings are drawn.
Live comparison across Maryland bridges with a recorded inventory load rating (5,479 of 5,484 rated).
BLACK ROCK RD vs every rated Maryland bridge
Inventory load rating (metric tons), FHWA NBI, this state
51 Top 37% higher than 63% of 5,479 bridges
rated Maryland bridges, bucketed by value
Each bar is a band; taller bars hold more bridges. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.
Source FHWA National Bridge Inventory · August 2026
Condition Ratings
Full 0–9 scale + sufficiency-rating breakdown: how condition ratings work.
Reported 0–9 component ratings from the FHWA NBI. The highlighted component is the lowest reported input to this record’s current condition category; it is not a closure or live crossing-safety decision.
Montgomery inventory by recorded NBI category
Exclusive Good/Fair/Poor bands across all 515 bridges in this county. Orthogonal to this structure's component profile above: a county catalog share, not a live crossing-safety verdict.
Structural Details
- Year Built
- 1965
- Last Reconstructed
- 1993
- Material
- Steel
- Number of Spans
- 2
- Structure Length
- 22.6 m (74 ft)
- Deck Width
- 4.6 m (15 ft)
- Owner
- County Highway Agency
- Avg Daily Traffic
- 373 vehicles/day
- Structure Number
- 200000M-0047010
Condition Analysis
- • At 6/9, the deck (driving surface) shows fair condition, with minor wear flagged for upkeep.
- • At 5/9, the superstructure (beams and supports above the deck) shows fair condition, with minor wear flagged for upkeep.
- • The substructure (piers and abutments) rates fair at 5/9, minor deterioration that routine maintenance should address.
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗How to read this record
This page shows what the last federal inspection recorded, not whether BLACK ROCK RD 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 BLACK ROCK RD against other structures in Montgomery and across Maryland. Maryland 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 BLACK ROCK RD?
BLACK ROCK RD in Montgomery, Maryland has a deck rating of 6/9, superstructure rating of 5/9, and substructure rating of 5/9 on the FHWA's 0–9 scale.
How often is BLACK ROCK RD inspected?
BLACK ROCK RD'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 373 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. BLACK ROCK RD 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 BLACK ROCK RD?
BLACK ROCK RD has an NBI inventory load rating of 51.2 metric tons.
Who is responsible for maintaining BLACK ROCK RD?
BLACK ROCK RD is owned and maintained by County Highway Agency.
How old is BLACK ROCK RD and does age affect safety?
BLACK ROCK RD was built in 1965, making it 61 years old and last reconstructed in 1993.
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.
Share this inspection record
Send this source-bounded record or download its data card. An NBI condition category is not a closure or live crossing-safety verdict.
Every figure on PlainBridges is rendered directly from federal source data, no number is typed in by an editor. Component ratings, ADT, and condition category on this page are copied from the NBI record for this structure; no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2024 NBI release. NBI condition categories reflect the latest reported inventory record, not a live safety, closure, or travel decision.