US Bridges

US 30 over I 84;NEW Plymouth Ic

Fair

Payette County, Idaho · 11.9 W. Caldwell · Structure no. 000000000013485

Built
1960
65 years old
Condition
Fair
inspected June 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
231 ft
5 main spans
Daily traffic
1,200
2023 count
Owner
State
State Highway Agency

About this bridge

US 30 over I 84;NEW Plymouth Ic is a prestressed concrete stringer/multi-beam or girder carrying US 30 over I 84;NEW Plymouth Ic in Payette County, Idaho. It was built in 1960, so it is 65 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 1,200 vehicles a day, roughly 35% of them trucks, projected to reach 1,800 by 2042. The structure is 231 ft (70.4 m) long and 33 ft wide. If it were closed, the detour would be 9.9 mi (16 km).

Location

Open in Google Maps
CarriesUS 30
CrossesI 84;NEW Plymouth Ic
Location11.9 W. Caldwell
RouteU.S. Route 30
CountyPayette County
StateIdaho
Coordinates43.90686, -116.81601
Functional classRural Major 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
Deck7 GoodSome minor problems.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionJune 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating60 US tons
Inventory rating36 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans5
Design loadHS 20
Structure length231 ft (70.4 m)
Longest span49 ft (14.8 m)
Deck width33 ft (10 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,200 (2023)
Projected traffic1,800 by 2042
Trucks35%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesOverpass structure at an interchange
CrossesHighway
Detour if closed9.9 mi (16 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$2.8 million (2019 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was US 30 over I 84;NEW Plymouth Ic built?

It was built in 1960, making it 65 years old in 2025.

What condition is US 30 over I 84;NEW Plymouth Ic 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 June 2023.

How much traffic does US 30 over I 84;NEW Plymouth Ic carry?

About 1,200 vehicles per day (2023 count), of which roughly 35% are trucks.

How long is US 30 over I 84;NEW Plymouth Ic?

The structure is 231 ft (70.4 m) long with a longest span of 49 ft (14.8 m) and a deck 33 ft wide.

Who owns US 30 over I 84;NEW Plymouth Ic?

It is owned by the State Highway Agency.