US Bridges

Lake Samish RD over I-5

Fair

Skagit County, Washington · 9.7 N JCT SR 11 · Structure no. 0007260C0000000

Built
1963
62 years old
Condition
Fair
inspected March 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
344 ft
4 main spans
Daily traffic
3,250
2012 count
Owner
State
State Highway Agency

About this bridge

Lake Samish RD over I-5 is a prestressed concrete stringer/multi-beam or girder carrying Lake Samish RD over I-5 in Skagit County, Washington. It was built in 1963, so it is 62 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 3,250 vehicles a day, roughly 5% of them trucks, projected to reach 5,200 by 2036. The structure is 344 ft (104.9 m) long and 33 ft wide. If it were closed, the detour would be 14.9 mi (24 km).

Location

Open in Google Maps
CarriesLake Samish RD
CrossesI-5
Location9.7 N JCT SR 11
RouteCounty Highway 0
CountySkagit County
StateWashington
Coordinates48.62156, -122.35708
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Last inspectionMarch 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Approach roadway alignment8: Equal to present desirable criteria
Operating rating68 US tons
Inventory rating41 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20
Structure length344 ft (104.9 m)
Longest span98 ft (29.9 m)
Deck width33 ft (10.2 m)
Roadway width26 ft (7.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,250 (2012)
Projected traffic5,200 by 2036
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesHighway
Detour if closed14.9 mi (24 km)
TollOn a free road
National Highway SystemNo

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$5.6 million (2022 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was Lake Samish RD over I-5 built?

It was built in 1963, making it 62 years old in 2025.

What condition is Lake Samish RD over I-5 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 March 2023.

How much traffic does Lake Samish RD over I-5 carry?

About 3,250 vehicles per day (2012 count), of which roughly 5% are trucks.

How long is Lake Samish RD over I-5?

The structure is 344 ft (104.9 m) long with a longest span of 98 ft (29.9 m) and a deck 33 ft wide.

Who owns Lake Samish RD over I-5?

It is owned by the State Highway Agency.