US Bridges

Boston Ave over Spring Gulch

Fair

Boulder County, Colorado · 0.1 Mile E. of Martin St. · Structure no. LONG-BOSTON-AVE

Built
2017
8 years old
Condition
Fair
inspected January 2025
Type
Culvert
Concrete
Length
25 ft
3 main spans
Daily traffic
978
2023 count
Owner
City
City or Municipal Highway Agency

About this bridge

Boston Ave over Spring Gulch is a concrete culvert carrying Boston Ave over Spring Gulch in Boulder County, Colorado. It was built in 2017, so it is 8 years old, younger 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 6 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 978 vehicles a day, roughly 13% of them trucks, projected to reach 1,174 by 2043. The structure is 25 ft (7.6 m) long and 108 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesBoston Ave
CrossesSpring Gulch
Location0.1 Mile E. of Martin St.
RouteCity Street 0
CountyBoulder County
StateColorado
Coordinates40.15783, -105.09402
Functional classUrban Collector

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Channel and channel protection8 Very GoodNo problems noted.
Culvert6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJanuary 2025
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating40 US tons
Inventory rating36 US tons

Structure

Structure typeCulvert
MaterialConcrete
DeckNot applicable
Main spans3
Design loadHL 93
Structure length25 ft (7.6 m)
Longest span8 ft (2.4 m)
Deck width108 ft (32.9 m)
Roadway width46 ft (14 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic978 (2023)
Projected traffic1,174 by 2043
Trucks13%
Lanes on structure3
Traffic directionTwo-way traffic
CarriesHighway
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—
NavigationNo navigation control on waterway

Frequently asked questions

When was Boston Ave over Spring Gulch built?

It was built in 2017, making it 8 years old in 2025.

What condition is Boston Ave over Spring Gulch 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 Boston Ave over Spring Gulch carry?

About 978 vehicles per day (2023 count), of which roughly 13% are trucks.

How long is Boston Ave over Spring Gulch?

The structure is 25 ft (7.6 m) long with a longest span of 8 ft (2.4 m) and a deck 108 ft wide.

Who owns Boston Ave over Spring Gulch?

It is owned by the City or Municipal Highway Agency.