US Bridges

N. Liberty Street over Ridenbaugh Canal

Fair

Ada County, Idaho · In Boise;n.Liberty St. · Structure no. 000000000026330

Built
1950
75 years old, rebuilt 1978
Condition
Fair
inspected March 2023
Type
Tee Beam
Prestressed Concrete
Length
30 ft
1 main span
Daily traffic
2,200
2023 count
Owner
County
County Highway Agency

About this bridge

N. Liberty Street over Ridenbaugh Canal is a prestressed concrete tee beam carrying N. Liberty Street over Ridenbaugh Canal in Ada County, Idaho. It was built in 1950 and reconstructed in 1978, so it is 75 years old, older than the Idaho average of 45.3 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 2,200 vehicles a day, projected to reach 3,300 by 2042. The structure is 30 ft (9.1 m) long and 32 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesN. Liberty Street
CrossesRidenbaugh Canal
LocationIn Boise;n.Liberty St.
RouteCity Street 0
CountyAda County
StateIdaho
Coordinates43.60436, -116.26128
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection7 GoodSome minor problems.
Last inspectionMarch 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourUnknown foundation; not evaluated for scour
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating53.6 US tons
Inventory rating38.7 US tons

Structure

Structure typeTee Beam
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length30 ft (9.1 m)
Longest span29 ft (8.8 m)
Deck width32 ft (9.8 m)
Roadway width30 ft (9.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,200 (2023)
Projected traffic3,300 by 2042
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was N. Liberty Street over Ridenbaugh Canal built?

It was built in 1950, making it 75 years old in 2025. It was reconstructed in 1978.

What condition is N. Liberty Street over Ridenbaugh Canal 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 March 2023.

How much traffic does N. Liberty Street over Ridenbaugh Canal carry?

About 2,200 vehicles per day (2023 count).

How long is N. Liberty Street over Ridenbaugh Canal?

The structure is 30 ft (9.1 m) long with a longest span of 29 ft (8.8 m) and a deck 32 ft wide.

Who owns N. Liberty Street over Ridenbaugh Canal?

It is owned by the County Highway Agency.