US Bridges

I 84 over SH 21;GOWEN RD Ic

Good

Ada County, Idaho · Boise Scl · Structure no. 000000000015771

Built
2015
10 years old
Condition
Good
inspected November 2022
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
175 ft
1 main span
Daily traffic
52,000
2023 count
Owner
State
State Highway Agency

About this bridge

I 84 over SH 21;GOWEN RD Ic is a prestressed concrete stringer/multi-beam or girder carrying I 84 over SH 21;GOWEN RD Ic in Ada County, Idaho. It was built in 2015, so it is 10 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 52,000 vehicles a day, roughly 24% of them trucks, projected to reach 78,000 by 2042. The structure is 175 ft (53.3 m) long and 117 ft wide.

Location

Open in Google Maps
CarriesI 84
CrossesSH 21;GOWEN RD Ic
LocationBoise Scl
RouteInterstate 84
CountyAda County
StateIdaho
Coordinates43.54222, -116.16111
Functional classUrban Principal Arterial - Interstate

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.
Substructure7 GoodSome minor problems.
Last inspectionNovember 2022
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating77.5 US tons
Inventory rating60 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHL 93
Structure length175 ft (53.3 m)
Longest span170 ft (51.8 m)
Deck width117 ft (35.7 m)
Roadway width96 ft (29.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic52,000 (2023)
Projected traffic78,000 by 2042
Trucks24%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
Detour if closed—
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

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 I 84 over SH 21;GOWEN RD Ic built?

It was built in 2015, making it 10 years old in 2025.

What condition is I 84 over SH 21;GOWEN RD 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 November 2022.

How much traffic does I 84 over SH 21;GOWEN RD Ic carry?

About 52,000 vehicles per day (2023 count), of which roughly 24% are trucks.

How long is I 84 over SH 21;GOWEN RD Ic?

The structure is 175 ft (53.3 m) long with a longest span of 170 ft (51.8 m) and a deck 117 ft wide.

Who owns I 84 over SH 21;GOWEN RD Ic?

It is owned by the State Highway Agency.