South Bowen Street
Carrying South Bowen Street over Left Hand Creek
At Missouri Ave, Boulder, Colorado
Inventory: FHWA NBI 2024 · last ETL August 2026
FHWA NBI record, refreshed with each annual release.
South Bowen Street in Boulder, Colorado sits above 42% of rated Colorado bridges on inventory load rating (33 t), while its 1965 build year is earlier than 84% of Boulder's recorded-year cohort (311 bridges).
South Bowen Street in Boulder, Colorado is rated Poor 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 4. The lowest applicable rating sets the federal condition category, so this Poor 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-SBOW-MIS
INTERSTATE-ERA · PRESTRESS · SINGLE-SPAN · DECK-LED · ARTERIAL-ADT · STANDARD-LOAD · CAT-POOR
- INTERSTATE-ERA 1950–1979
- PRESTRESS Prestressed concrete
- SINGLE-SPAN Single span
- DECK-LED Deck-led
- ARTERIAL-ADT Arterial ADT
- STANDARD-LOAD Standard load
- CAT-POOR Poor
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: South Bowen Street
The South Bowen Street bridge in Boulder, Colorado carries South Bowen Street over Left Hand Creek. It was built in 1965, making it 61 years old today. The structure is built primarily of prestressed concrete and spans 1 section, stretching 9.4 meters (31 feet) end to end. Daily traffic averages 1,835 vehicles, placing it in the moderately-trafficked tier of Colorado bridges. It is owned and maintained by City/Municipal Highway Agency.
The latest FHWA inspection records show a deck rating of 4/9, superstructure at 5/9, substructure at 6/9. The weakest component sits in poor condition. At least one major component here scores 4 or below, which produces a Poor condition classification under FHWA's current reporting rules.
How South Bowen Street compares
Age against the county: built in 1965, earlier than 260 of Boulder's 311 bridges with a recorded construction year (84%), against a county median build year of 1990. Age is not a defect on its own, but it is the population from which future Poor ratings are drawn.
Live comparison across Colorado bridges with a recorded inventory load rating (8,962 of 8,965 rated).
South Bowen Street vs every rated Colorado bridge
Inventory load rating (metric tons), FHWA NBI, this state
33 Top 58% higher than 42% 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.
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.
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
- 1965
- Material
- Prestressed Concrete
- Number of Spans
- 1
- Structure Length
- 9.4 m (31 ft)
- Deck Width
- 12.2 m (40 ft)
- Owner
- City/Municipal Highway Agency
- Avg Daily Traffic
- 1,835 vehicles/day
- Structure Number
- LONG-SBOW-MIS
Condition Analysis
- • The deck (driving surface) is in poor condition (4/9), showing advanced deterioration on the inspecting agency's 0-9 scale.
- • The superstructure (beams and supports above the deck) is in fair condition (5/9), with minor deterioration that may require routine maintenance.
- • At 6/9, the substructure (piers and abutments) shows fair condition, with minor wear flagged for upkeep.
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗How to read this record
South Bowen Street is in the federal Poor condition category. That is a component-based result, not a closure order.
- NBI condition ratings reflect the latest record in this annual dataset, not a live status. Current routine inspection intervals are risk-based.
- Understand what Poor condition does and does not mean before drawing conclusions. Poor condition explained
- Compare South Bowen Street 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 South Bowen Street?
South Bowen Street in Boulder, Colorado has a deck rating of 4/9, superstructure rating of 5/9, and substructure rating of 6/9 on the FHWA's 0–9 scale.
How often is South Bowen Street inspected?
South Bowen Street'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 1,835 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. South Bowen Street is currently shown as Poor condition from its component ratings; that category is not a live closure or safety decision.
What is the inventory load rating for South Bowen Street?
South Bowen Street has an NBI inventory load rating of 32.7 metric tons.
Who is responsible for maintaining South Bowen Street?
South Bowen Street is owned and maintained by City/Municipal Highway Agency.
How old is South Bowen Street and does age affect safety?
South Bowen Street was built in 1965, making it 61 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.