US Bridges

County Line Road over Spring Gulch #2

Good

Boulder County, Colorado · 0.20 MI N. of E 9th Ave · Structure no. LONG-CLR-E9TH

Built
2021
4 years old
Condition
Good
inspected January 2025
Type
Culvert
Concrete
Length
33 ft
2 main spans
Daily traffic
15,509
2023 count
Owner
City
City or Municipal Highway Agency

About this bridge

County Line Road over Spring Gulch #2 is a concrete culvert carrying County Line Road over Spring Gulch #2 in Boulder County, Colorado. It was built in 2021, so it is 4 years old, younger than the Colorado average of 42.2 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 15,509 vehicles a day, roughly 9% of them trucks, projected to reach 18,611 by 2042. The structure is 33 ft (10.1 m) long and 93 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

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CarriesCounty Line Road
CrossesSpring Gulch #2
Location0.20 MI N. of E 9th Ave
RouteCity Street 0
CountyBoulder County
StateColorado
Coordinates40.17722, -105.0554
Functional classUrban Other Principal Arterial

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Channel and channel protection8 Very GoodNo problems noted.
Culvert7 GoodSome minor problems.
Last inspectionJanuary 2025
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry9: Superior to present desirable criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating55 US tons
Inventory rating42.5 US tons

Structure

Structure typeCulvert
MaterialConcrete
DeckNot applicable
Main spans2
Design loadHL 93
Structure length33 ft (10.1 m)
Longest span13 ft (4 m)
Deck width93 ft (28.2 m)
Roadway width73 ft (22.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic15,509 (2023)
Projected traffic18,611 by 2042
Trucks9%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed1.9 mi (3 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNot applicable (no waterway)

Frequently asked questions

When was County Line Road over Spring Gulch #2 built?

It was built in 2021, making it 4 years old in 2025.

What condition is County Line Road over Spring Gulch #2 in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in January 2025.

How much traffic does County Line Road over Spring Gulch #2 carry?

About 15,509 vehicles per day (2023 count), of which roughly 9% are trucks.

How long is County Line Road over Spring Gulch #2?

The structure is 33 ft (10.1 m) long with a longest span of 13 ft (4 m) and a deck 93 ft wide.

Who owns County Line Road over Spring Gulch #2?

It is owned by the City or Municipal Highway Agency.