County Line Road
Carrying County Line Road over Spring Gulch #2
0.20 MI N. OF E 9TH AVE, Boulder, Colorado
Inventory: FHWA NBI 2024 · last ETL August 2026
FHWA NBI record, refreshed with each annual release.
County Line Road in Boulder, Colorado sits above 69% of rated Colorado bridges on inventory load rating (39 t), while its 2021 build year is earlier than 0% of Boulder's recorded-year cohort (311 bridges).
County Line Road in Boulder, Colorado is rated Good in the FHWA's 2024 National Bridge Inventory. Built in 2021, it carries 1 rated component on the inspecting agency's 0-9 scale, and its weakest reported component scores 7. The lowest applicable rating sets the federal condition category, so this Good 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 CO:LONG-CLR-E9TH
POST-2000 · CONCRETE · MULTI-SPAN · CULVERT-LED · HEAVY-ADT · STANDARD-LOAD · CAT-GOOD
- POST-2000 2000+
- CONCRETE Concrete
- MULTI-SPAN 2 spans
- CULVERT-LED Culvert-led
- HEAVY-ADT Heavy ADT
- STANDARD-LOAD Standard load
- CAT-GOOD Good
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: County Line Road
The County Line Road bridge in Boulder, Colorado carries County Line Road over Spring Gulch #2. It was built in 2021, making it 5 years old today. The structure is built primarily of concrete and spans 2 sections, stretching 10.1 meters (33 feet) end to end. Daily traffic averages 15,509 vehicles, placing it in the heavily-trafficked tier of Colorado bridges. It is owned and maintained by City/Municipal Highway Agency.
The latest FHWA inspection records show culvert at 7/9. The weakest component sits in good condition. All reported major components score above the Poor range.
How County Line Road compares
Age against the county: built in 2021, earlier than 1 of Boulder's 311 bridges with a recorded construction year (0%), against a county median build year of 1990. This is one of the newer structures in its county.
Live comparison across Colorado bridges with a recorded inventory load rating (8,962 of 8,965 rated).
County Line Road vs every rated Colorado bridge
Inventory load rating (metric tons), FHWA NBI, this state
39 Top 31% higher than 69% of 8,962 bridges
rated Colorado 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.
Boulder inventory by recorded NBI category
Exclusive Good/Fair/Poor bands across all 311 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
- 2021
- Material
- Concrete
- Number of Spans
- 2
- Structure Length
- 10.1 m (33 ft)
- Deck Width
- 28.2 m (93 ft)
- Owner
- City/Municipal Highway Agency
- Avg Daily Traffic
- 15,509 vehicles/day
- Structure Number
- LONG-CLR-E9TH
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 County Line Road 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 County Line Road against other structures in Boulder and across Colorado. Colorado 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 County Line Road?
County Line Road in Boulder, Colorado on the FHWA's 0–9 scale.
How often is County Line Road inspected?
County Line Road'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 15,509 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. County Line Road is currently shown as Good condition from its component ratings; that category is not a live closure or safety decision.
What is the inventory load rating for County Line Road?
County Line Road has an NBI inventory load rating of 38.6 metric tons.
Who is responsible for maintaining County Line Road?
County Line Road is owned and maintained by City/Municipal Highway Agency.
How old is County Line Road and does age affect safety?
County Line Road was built in 2021, making it 5 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.