US Bridges

SH 55 over I 84;KARCHER-MIDLAND Ic

Good

Canyon County, Idaho · In Nampa · Structure no. 000000000014729

Built
2006
19 years old
Condition
Good
inspected February 2022
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
201 ft
2 main spans
Daily traffic
36,000
2023 count
Owner
State
State Highway Agency

About this bridge

SH 55 over I 84;KARCHER-MIDLAND Ic is a prestressed concrete stringer/multi-beam or girder carrying SH 55 over I 84;KARCHER-MIDLAND Ic in Canyon County, Idaho. It was built in 2006, so it is 19 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 36,000 vehicles a day, roughly 3% of them trucks, projected to reach 54,000 by 2042. The structure is 201 ft (61.3 m) long and 81 ft wide.

Location

Open in Google Maps
CarriesSH 55
CrossesI 84;KARCHER-MIDLAND Ic
LocationIn Nampa
RouteState Highway 55
CountyCanyon County
StateIdaho
Coordinates43.60975, -116.59692
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
Deck7 GoodSome minor problems.
Superstructure8 Very GoodNo problems noted.
Substructure8 Very GoodNo problems noted.
Last inspectionFebruary 2022
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation8: Equal to present desirable criteria
Deck geometry9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating99.9 US tons
Inventory rating50 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans2
Design loadHL 93
Structure length201 ft (61.3 m)
Longest span104 ft (31.7 m)
Deck width81 ft (24.8 m)
Roadway width73 ft (22.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic36,000 (2023)
Projected traffic54,000 by 2042
Trucks3%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
Detour if closed—
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—
NavigationNot applicable (no waterway)

Frequently asked questions

When was SH 55 over I 84;KARCHER-MIDLAND Ic built?

It was built in 2006, making it 19 years old in 2025.

What condition is SH 55 over I 84;KARCHER-MIDLAND Ic 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 February 2022.

How much traffic does SH 55 over I 84;KARCHER-MIDLAND Ic carry?

About 36,000 vehicles per day (2023 count), of which roughly 3% are trucks.

How long is SH 55 over I 84;KARCHER-MIDLAND Ic?

The structure is 201 ft (61.3 m) long with a longest span of 104 ft (31.7 m) and a deck 81 ft wide.

Who owns SH 55 over I 84;KARCHER-MIDLAND Ic?

It is owned by the State Highway Agency.