US Bridges

SR 20 over Half Br Sta 163

Fair

Whatcom County, Washington · 6.1 E Skagit CO · Structure no. 0006974C0000000

Built
1962
63 years old
Condition
Fair
inspected July 2023
Type
Slab
Concrete
Length
78 ft
1 main span
Daily traffic
1,696
2023 count
Owner
State
State Highway Agency

About this bridge

SR 20 over Half Br Sta 163 is a concrete slab carrying SR 20 over Half Br Sta 163 in Whatcom County, Washington. It was built in 1962, so it is 63 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 1,696 vehicles a day, roughly 7% of them trucks, projected to reach 2,442 by 2039. The structure is 78 ft (23.8 m) long and 12 ft wide. If it were closed, the detour would be 98.8 mi (159 km).

Location

Open in Google Maps
CarriesSR 20
CrossesHalf Br Sta 163
Location6.1 E Skagit CO
RouteState Highway 20
CountyWhatcom County
StateWashington
Coordinates48.6923, -121.22348
Functional classRural Minor Arterial

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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure7 GoodSome minor problems.
Last inspectionJuly 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
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
Approach roadway alignment6: Equal to present minimum criteria
Operating rating58 US tons
Inventory rating34 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length78 ft (23.8 m)
Longest span76 ft (23.2 m)
Deck width12 ft (3.6 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,696 (2023)
Projected traffic2,442 by 2039
Trucks7%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesOther
Detour if closed98.8 mi (159 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$963,000 (2022 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was SR 20 over Half Br Sta 163 built?

It was built in 1962, making it 63 years old in 2025.

What condition is SR 20 over Half Br Sta 163 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 July 2023.

How much traffic does SR 20 over Half Br Sta 163 carry?

About 1,696 vehicles per day (2023 count), of which roughly 7% are trucks.

How long is SR 20 over Half Br Sta 163?

The structure is 78 ft (23.8 m) long with a longest span of 76 ft (23.2 m) and a deck 12 ft wide.

Who owns SR 20 over Half Br Sta 163?

It is owned by the State Highway Agency.