US Bridges

SH 55 over Power Canal

Good

Boise County, Idaho · Horseshoe Bend · Structure no. 000000000014766

Built
1994
31 years old
Condition
Good
inspected October 2022
Type
Slab
Concrete Continuous
Length
100 ft
4 main spans
Daily traffic
8,800
2023 count
Owner
State
State Highway Agency

About this bridge

SH 55 over Power Canal is a concrete continuous slab carrying SH 55 over Power Canal in Boise County, Idaho. It was built in 1994, so it is 31 years old, younger than the Idaho average of 45.3 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 8,800 vehicles a day, roughly 5% of them trucks, projected to reach 13,200 by 2042. The structure is 100 ft (30.5 m) long and 74 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

Open in Google Maps
CarriesSH 55
CrossesPower Canal
LocationHorseshoe Bend
RouteState Highway 55
CountyBoise County
StateIdaho
Coordinates43.91108, -116.19911
Functional classRural Principal Arterial - Other

Condition and inspection

Good

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

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionOctober 2022
Inspection intervalevery 48 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 rating79 US tons
Inventory rating47 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadHS 25 or greater
Structure length100 ft (30.5 m)
Longest span24 ft (7.3 m)
Deck width74 ft (22.6 m)
Roadway width72 ft (21.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic8,800 (2023)
Projected traffic13,200 by 2042
Trucks5%
Lanes on structure3
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed5 mi (8 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState 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 SH 55 over Power Canal built?

It was built in 1994, making it 31 years old in 2025.

What condition is SH 55 over Power Canal 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 October 2022.

How much traffic does SH 55 over Power Canal carry?

About 8,800 vehicles per day (2023 count), of which roughly 5% are trucks.

How long is SH 55 over Power Canal?

The structure is 100 ft (30.5 m) long with a longest span of 24 ft (7.3 m) and a deck 74 ft wide.

Who owns SH 55 over Power Canal?

It is owned by the State Highway Agency.