US Bridges

US 101 over Kennedy Creek

Fair

Mason County, Washington · 2.7 S JCT SR 108 · Structure no. 0006383B0000000

Built
1960
65 years old
Condition
Fair
inspected October 2024
Type
Slab
Concrete Continuous
Length
129 ft
3 main spans
Daily traffic
13,297
2023 count
Owner
State
State Highway Agency

About this bridge

US 101 over Kennedy Creek is a concrete continuous slab carrying US 101 over Kennedy Creek in Mason County, Washington. It was built in 1960, so it is 65 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 13,297 vehicles a day, roughly 7% of them trucks, projected to reach 18,311 by 2039. The structure is 129 ft (39.3 m) long and 33 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesUS 101
CrossesKennedy Creek
Location2.7 S JCT SR 108
RouteU.S. Route 101
CountyMason County
StateWashington
Coordinates47.09678, -123.08614
Functional classRural Principal Arterial - Other

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck8 Very GoodNo problems noted.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation6: Equal to present minimum criteria
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating50 US tons
Inventory rating38.6 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length129 ft (39.3 m)
Longest span50 ft (15.2 m)
Deck width33 ft (10.2 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic13,297 (2023)
Projected traffic18,311 by 2039
Trucks7%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes

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$2.8 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was US 101 over Kennedy Creek built?

It was built in 1960, making it 65 years old in 2025.

What condition is US 101 over Kennedy Creek 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 October 2024.

How much traffic does US 101 over Kennedy Creek carry?

About 13,297 vehicles per day (2023 count), of which roughly 7% are trucks.

How long is US 101 over Kennedy Creek?

The structure is 129 ft (39.3 m) long with a longest span of 50 ft (15.2 m) and a deck 33 ft wide.

Who owns US 101 over Kennedy Creek?

It is owned by the State Highway Agency.