US Bridges

US 12 over I-5

Good

Thurston County, Washington · 7.7 E Grays Hbr CO · Structure no. 0017998B0000000

Built
2011
14 years old
Condition
Good
inspected November 2021
Type
Tee Beam
Prestressed Concrete Continuous
Length
176 ft
2 main spans
Daily traffic
16,270
2023 count
Owner
State
State Highway Agency

About this bridge

US 12 over I-5 is a prestressed concrete continuous tee beam carrying US 12 over I-5 in Thurston County, Washington. It was built in 2011, so it is 14 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 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 16,270 vehicles a day, roughly 9% of them trucks, projected to reach 23,964 by 2039. The structure is 176 ft (53.6 m) long and 87 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

Open in Google Maps
CarriesUS 12
CrossesI-5
Location7.7 E Grays Hbr CO
RouteU.S. Route 12
CountyThurston County
StateWashington
Coordinates46.80269, -123.00756
Functional classUrban Principal Arterial - Other Freeway or Expressway

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 2021
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating61 US tons
Inventory rating36 US tons

Structure

Structure typeTee Beam
MaterialPrestressed Concrete Continuous
DeckConcrete, cast-in-place
Main spans2
Design loadHL 93
Structure length176 ft (53.6 m)
Longest span86 ft (26.2 m)
Deck width87 ft (26.5 m)
Roadway width71 ft (21.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic16,270 (2023)
Projected traffic23,964 by 2039
Trucks9%
Lanes on structure5
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesHighway
Detour if closed6.2 mi (10 km)
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 proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$6.1 million (2022 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was US 12 over I-5 built?

It was built in 2011, making it 14 years old in 2025.

What condition is US 12 over I-5 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 2021.

How much traffic does US 12 over I-5 carry?

About 16,270 vehicles per day (2023 count), of which roughly 9% are trucks.

How long is US 12 over I-5?

The structure is 176 ft (53.6 m) long with a longest span of 86 ft (26.2 m) and a deck 87 ft wide.

Who owns US 12 over I-5?

It is owned by the State Highway Agency.