US Bridges

20th ST NE over Catherine Creek

Good

Snohomish County, Washington · 0.38 E JCT 124th Av NE · Structure no. 086277000000000

Built
1997
28 years old
Condition
Good
inspected October 2023
Type
Stringer/Multi-beam or Girder
Concrete Continuous
Length
70 ft
1 main span
Daily traffic
3,192
2023 count
Owner
City
City or Municipal Highway Agency

About this bridge

20th ST NE over Catherine Creek is a concrete continuous stringer/multi-beam or girder carrying 20th ST NE over Catherine Creek in Snohomish County, Washington. It was built in 1997, so it is 28 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 3,192 vehicles a day, roughly 5% of them trucks, projected to reach 6,000 by 2045. The structure is 70 ft (21.3 m) long and 48 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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Carries20th ST NE
CrossesCatherine Creek
Location0.38 E JCT 124th Av NE
RouteCity Street 660
CountySnohomish County
StateWashington
Coordinates48.01544, -122.05569
Functional classUrban Minor Arterial

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.
Substructure8 Very GoodNo problems noted.
Channel and channel protection7 GoodSome minor problems.
Last inspectionOctober 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation8: Equal to present desirable criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating100 US tons
Inventory rating60 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans1
Design loadHS 25 or greater
Structure length70 ft (21.3 m)
Longest span65 ft (19.9 m)
Deck width48 ft (14.6 m)
Roadway width36 ft (11 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,192 (2023)
Projected traffic6,000 by 2045
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedOther structural work, including hydraulic replacements
Estimated improvement cost$864,000 (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was 20th ST NE over Catherine Creek built?

It was built in 1997, making it 28 years old in 2025.

What condition is 20th ST NE over Catherine Creek 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 October 2023.

How much traffic does 20th ST NE over Catherine Creek carry?

About 3,192 vehicles per day (2023 count), of which roughly 5% are trucks.

How long is 20th ST NE over Catherine Creek?

The structure is 70 ft (21.3 m) long with a longest span of 65 ft (19.9 m) and a deck 48 ft wide.

Who owns 20th ST NE over Catherine Creek?

It is owned by the City or Municipal Highway Agency.