US Bridges

4th Ave NW over North Fork Issaquah CR

Good

King County, Washington · 0.3 MI N of Gilman · Structure no. 088267000000000

Built
2011
14 years old
Condition
Good
inspected October 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
43 ft
1 main span
Daily traffic
5,500
2019 count
Owner
City
City or Municipal Highway Agency

About this bridge

4th Ave NW over North Fork Issaquah CR is a prestressed concrete stringer/multi-beam or girder carrying 4th Ave NW over North Fork Issaquah CR in King 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 5,500 vehicles a day, roughly 5% of them trucks, projected to reach 11,000 by 2039. The structure is 43 ft (13.1 m) long and 61 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Carries4th Ave NW
CrossesNorth Fork Issaquah CR
Location0.3 MI N of Gilman
RouteCity Street 590
Coordinates47.54603, -122.04178
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.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation7: Better than present minimum 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 rating55.7 US tons
Inventory rating36.4 US tons

Structure

MaterialPrestressed Concrete
DeckOther
Main spans1
Design loadHS 25 or greater
Structure length43 ft (13.1 m)
Longest span38 ft (11.6 m)
Deck width61 ft (18.6 m)
Roadway width48 ft (14.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic5,500 (2019)
Projected traffic11,000 by 2039
Trucks5%
Lanes on structure3
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed1.9 mi (3 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$817,000 (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was 4th Ave NW over North Fork Issaquah CR built?

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

What condition is 4th Ave NW over North Fork Issaquah CR 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 2024.

How much traffic does 4th Ave NW over North Fork Issaquah CR carry?

About 5,500 vehicles per day (2019 count), of which roughly 5% are trucks.

How long is 4th Ave NW over North Fork Issaquah CR?

The structure is 43 ft (13.1 m) long with a longest span of 38 ft (11.6 m) and a deck 61 ft wide.

Who owns 4th Ave NW over North Fork Issaquah CR?

It is owned by the City or Municipal Highway Agency.