120th Street over Coal Creek
FairBoulder County, Colorado · 0.25 M S of S. Boulder RD · Structure no. LAF-120TH-002
- Built
- 1977
- 48 years old
- Condition
- Fair
- inspected January 2025
- Type
- Culvert
- Concrete
- Length
- 45 ft
- 3 main spans
- Daily traffic
- 8,097
- 2023 count
- Owner
- City
- City or Municipal Highway Agency
About this bridge
120th Street over Coal Creek is a concrete culvert carrying 120th Street over Coal Creek in Boulder County, Colorado. It was built in 1977, so it is 48 years old, older than the Colorado average of 42.2 years.
The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 5 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.
It carries about 8,097 vehicles a day, roughly 24% of them trucks, projected to reach 9,716 by 2043. The structure is 45 ft (13.7 m) long and 34 ft wide. If it were closed, the detour would be 1.9 mi (3 km).
Location
Open in Google MapsCondition and inspection
The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.
| Component | Rating | Meaning |
|---|---|---|
| Channel and channel protection | 7 Good | Some minor problems. |
| Culvert | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was 120th Street over Coal Creek built?
It was built in 1977, making it 48 years old in 2025.
What condition is 120th Street over Coal Creek in?
The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in January 2025.
How much traffic does 120th Street over Coal Creek carry?
About 8,097 vehicles per day (2023 count), of which roughly 24% are trucks.
How long is 120th Street over Coal Creek?
The structure is 45 ft (13.7 m) long with a longest span of 16 ft (5 m) and a deck 34 ft wide.
Who owns 120th Street over Coal Creek?
It is owned by the City or Municipal Highway Agency.