US Bridges

Steilacoom Road over Mcallister Creek

Fair

Thurston County, Washington · 2.0 M S of I-5 on Ramp · Structure no. 082390000000000

Built
1964
61 years old
Condition
Fair
inspected September 2023
Type
Slab
Concrete Continuous
Length
128 ft
4 main spans
Daily traffic
1,384
2019 count
Owner
County
County Highway Agency

About this bridge

Steilacoom Road over Mcallister Creek is a concrete continuous slab carrying Steilacoom Road over Mcallister Creek in Thurston County, Washington. It was built in 1964, so it is 61 years old, older than the Washington average of 49.8 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 1,384 vehicles a day, roughly 15% of them trucks, projected to reach 2,140 by 2041. The structure is 128 ft (39 m) long and 26 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

Open in Google Maps
CarriesSteilacoom Road
CrossesMcallister Creek
Location2.0 M S of I-5 on Ramp
RouteCounty Highway 14830
CountyThurston County
StateWashington
Coordinates47.04997, -122.72649
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.
Superstructure7 GoodSome minor problems.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection7 GoodSome minor problems.
Last inspectionSeptember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating68 US tons
Inventory rating40 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20
Structure length128 ft (39 m)
Longest span36 ft (11 m)
Deck width26 ft (8 m)
Roadway width24 ft (7.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,384 (2019)
Projected traffic2,140 by 2041
Trucks15%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed5 mi (8 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$5 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Steilacoom Road over Mcallister Creek built?

It was built in 1964, making it 61 years old in 2025.

What condition is Steilacoom Road over Mcallister Creek 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 2023.

How much traffic does Steilacoom Road over Mcallister Creek carry?

About 1,384 vehicles per day (2019 count), of which roughly 15% are trucks.

How long is Steilacoom Road over Mcallister Creek?

The structure is 128 ft (39 m) long with a longest span of 36 ft (11 m) and a deck 26 ft wide.

Who owns Steilacoom Road over Mcallister Creek?

It is owned by the County Highway Agency.