US Bridges

I 84 ;us 20-26 over Boise River;caldwell Br.

Fair

Canyon County, Idaho · In Caldwell · Structure no. 000000000015490

Built
1983
42 years old
Condition
Fair
inspected September 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
296 ft
3 main spans
Daily traffic
53,500
2023 count
Owner
State
State Highway Agency

About this bridge

I 84 ;us 20-26 over Boise River;caldwell Br. is a prestressed concrete stringer/multi-beam or girder carrying I 84 ;us 20-26 over Boise River;caldwell Br. in Canyon County, Idaho. It was built in 1983, so it is 42 years old, younger 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 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 53,500 vehicles a day, roughly 20% of them trucks, projected to reach 80,250 by 2042. The structure is 296 ft (90.2 m) long and 90 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesI 84 ;us 20-26
CrossesBoise River;caldwell Br.
LocationIn Caldwell
RouteInterstate 84
CountyCanyon County
StateIdaho
Coordinates43.68139, -116.68972
Functional classUrban Principal Arterial - Interstate

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.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionSeptember 2024
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to 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 rating46 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 25 or greater
Structure length296 ft (90.2 m)
Longest span97 ft (29.6 m)
Deck width90 ft (27.3 m)
Roadway width87 ft (26.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic53,500 (2023)
Projected traffic80,250 by 2042
Trucks20%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.9 mi (3 km)
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—
NavigationNo navigation control on waterway

Frequently asked questions

When was I 84 ;us 20-26 over Boise River;caldwell Br. built?

It was built in 1983, making it 42 years old in 2025.

What condition is I 84 ;us 20-26 over Boise River;caldwell Br. 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 September 2024.

How much traffic does I 84 ;us 20-26 over Boise River;caldwell Br. carry?

About 53,500 vehicles per day (2023 count), of which roughly 20% are trucks.

How long is I 84 ;us 20-26 over Boise River;caldwell Br.?

The structure is 296 ft (90.2 m) long with a longest span of 97 ft (29.6 m) and a deck 90 ft wide.

Who owns I 84 ;us 20-26 over Boise River;caldwell Br.?

It is owned by the State Highway Agency.