US Bridges

I-5 over SR 121 & Railroad

Good

Thurston County, Washington · 6.9 N JCT US 12 · Structure no. 0017465D0000000

Built
2010
15 years old
Condition
Good
inspected June 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete Continuous
Length
220 ft
3 main spans
Daily traffic
33,313
2023 count
Owner
State
State Highway Agency

About this bridge

I-5 over SR 121 & Railroad is a prestressed concrete continuous stringer/multi-beam or girder carrying I-5 over SR 121 & Railroad in Thurston County, Washington. It was built in 2010, so it is 15 years old, younger than the Washington average of 49.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 8 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 33,313 vehicles a day, roughly 17% of them trucks, projected to reach 48,132 by 2039. The structure is 220 ft (67.1 m) long and 143 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesI-5
CrossesSR 121 & Railroad
Location6.9 N JCT US 12
RouteInterstate 5
CountyThurston County
StateWashington
Coordinates46.89647, -122.96072
Functional classRural 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
Deck8 Very GoodNo problems noted.
Superstructure8 Very GoodNo problems noted.
Substructure8 Very GoodNo problems noted.
Last inspectionJune 2024
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 rating59.3 US tons
Inventory rating45 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHL 93
Structure length220 ft (67.1 m)
Longest span75 ft (22.9 m)
Deck width143 ft (43.6 m)
Roadway width138 ft (42.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic33,313 (2023)
Projected traffic48,132 by 2039
Trucks17%
Lanes on structure8
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway and railroad
Detour if closed1.2 mi (2 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 proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$14.6 million (2022 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was I-5 over SR 121 & Railroad built?

It was built in 2010, making it 15 years old in 2025.

What condition is I-5 over SR 121 & Railroad 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 June 2024.

How much traffic does I-5 over SR 121 & Railroad carry?

About 33,313 vehicles per day (2023 count), of which roughly 17% are trucks.

How long is I-5 over SR 121 & Railroad?

The structure is 220 ft (67.1 m) long with a longest span of 75 ft (22.9 m) and a deck 143 ft wide.

Who owns I-5 over SR 121 & Railroad?

It is owned by the State Highway Agency.