MD 550
Carrying MD 550 over CABBAGE RUN
1.39 MILES NORTH OF MD 26, Frederick, Maryland
Inventory: FHWA NBI 2024 · last ETL August 2026
FHWA NBI record, refreshed with each annual release.
MD 550 in Frederick, Maryland sits above 1% of rated Maryland bridges on inventory load rating (15 t), while its 1939 build year is earlier than 85% of Frederick's recorded-year cohort (486 bridges).
MD 550 in Frederick, Maryland is rated Fair in the FHWA's 2024 National Bridge Inventory. Built in 1939, it carries 1 rated component on the inspecting agency's 0-9 scale, and its weakest reported component scores 6. 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:100000100096020
PRE-1950 · CONCRETE · SHORT-BRIDGE · CULVERT-LED · ARTERIAL-ADT · LIGHT-LOAD · CAT-FAIR
- PRE-1950 Pre-1950
- CONCRETE Concrete
- SHORT-BRIDGE 8.2 m
- CULVERT-LED Culvert-led
- ARTERIAL-ADT Arterial ADT
- LIGHT-LOAD Light 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: MD 550
The MD 550 bridge in Frederick, Maryland carries MD 550 over CABBAGE RUN. It was built in 1939, making it 87 years old today. The structure is built primarily of concrete, stretching 8.2 meters (27 feet) end to end. Daily traffic averages 2,785 vehicles, placing it in the moderately-trafficked tier of Maryland bridges. It is owned and maintained by State Highway Agency.
The latest FHWA inspection records show culvert at 6/9. The weakest component sits in fair condition. No reported major component scores in the Poor range under the current federal condition thresholds.
How MD 550 compares
Age against the county: built in 1939, earlier than 411 of Frederick's 486 bridges with a recorded construction year (85%), against a county median build year of 1976. 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).
MD 550 vs every rated Maryland bridge
Inventory load rating (metric tons), FHWA NBI, this state
15 Top 99% higher than 1% 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.
Frederick inventory by recorded NBI category
Exclusive Good/Fair/Poor bands across all 486 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
- 1939
- Material
- Concrete
- Structure Length
- 8.2 m (27 ft) 0
- Owner
- State Highway Agency
- Avg Daily Traffic
- 2,785 vehicles/day
- Structure Number
- 100000100096020
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 MD 550 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 MD 550 against other structures in Frederick 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 MD 550?
MD 550 in Frederick, Maryland on the FHWA's 0–9 scale.
How often is MD 550 inspected?
MD 550'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 2,785 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. MD 550 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 MD 550?
MD 550 has an NBI inventory load rating of 14.5 metric tons.
Who is responsible for maintaining MD 550?
MD 550 is owned and maintained by State Highway Agency.
How old is MD 550 and does age affect safety?
MD 550 was built in 1939, making it 87 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.
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.