US Bridges

North Herron RD NW over Herron Bay

Fair

Pierce County, Washington · 3.2 W JCT Key Penninsula · Structure no. 083726000000000

Built
1954
71 years old
Condition
Fair
inspected June 2023
Type
Slab
Concrete Continuous
Length
60 ft
3 main spans
Daily traffic
350
2021 count
Owner
County
County Highway Agency

About this bridge

North Herron RD NW over Herron Bay is a concrete continuous slab carrying North Herron RD NW over Herron Bay in Pierce County, Washington. It was built in 1954, so it is 71 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 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 350 vehicles a day, roughly 3% of them trucks, projected to reach 700 by 2042. The structure is 60 ft (18.3 m) long and 24 ft wide. If it were closed, the detour would be 98.8 mi (159 km).

Location

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CarriesNorth Herron RD NW
CrossesHerron Bay
Location3.2 W JCT Key Penninsula
RouteCounty Highway 22100
CountyPierce County
StateWashington
Coordinates47.27404, -122.81189
Functional classRural Local

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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJune 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating48.9 US tons
Inventory rating29 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadH 15
Structure length60 ft (18.3 m)
Longest span20 ft (6.1 m)
Deck width24 ft (7.3 m)
Roadway width22 ft (6.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic350 (2021)
Projected traffic700 by 2042
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed98.8 mi (159 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$2.1 million (2020 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was North Herron RD NW over Herron Bay built?

It was built in 1954, making it 71 years old in 2025.

What condition is North Herron RD NW over Herron Bay 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 North Herron RD NW over Herron Bay carry?

About 350 vehicles per day (2021 count), of which roughly 3% are trucks.

How long is North Herron RD NW over Herron Bay?

The structure is 60 ft (18.3 m) long with a longest span of 20 ft (6.1 m) and a deck 24 ft wide.

Who owns North Herron RD NW over Herron Bay?

It is owned by the County Highway Agency.