US Bridges

US101(HWY009) over Coalbank Slough

Fair

Coos County, Oregon · 03.8 MI S HWY 240 JCT · Structure no. 02478C009 23920

Built
1987
38 years old
Condition
Fair
inspected May 2023
Type
Slab
Concrete Continuous
Length
362 ft
6 main spans
Daily traffic
31,461
2022 count
Owner
State
State Highway Agency

About this bridge

US101(HWY009) over Coalbank Slough is a concrete continuous slab carrying US101(HWY009) over Coalbank Slough in Coos County, Oregon. It was built in 1987, so it is 38 years old, younger than the Oregon average of 49.9 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 31,461 vehicles a day, roughly 7% of them trucks, projected to reach 32,900 by 2042. The structure is 362 ft (110.3 m) long and 87 ft wide. If it were closed, the detour would be 6.8 mi (11 km).

Location

Open in Google Maps
CarriesUS101(HWY009)
CrossesCoalbank Slough
Location03.8 MI S HWY 240 JCT
RouteU.S. Route 101
CountyCoos County
StateOregon
Coordinates43.35606, -124.20941
Functional classUrban Other Principal 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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionMay 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; action required to protect exposed foundations
Structural evaluation6: Equal to present minimum criteria
Deck geometry9: Superior to present desirable criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating45 US tons
Inventory rating34.6 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans6
Design loadHS 25 or greater
Structure length362 ft (110.3 m)
Longest span70 ft (21.3 m)
Deck width87 ft (26.6 m)
Roadway width72 ft (21.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic31,461 (2022)
Projected traffic32,900 by 2042
Trucks7%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed6.8 mi (11 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkNon-Interstate STRAHNET route

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNavigation control on waterway (bridge permit required)

Frequently asked questions

When was US101(HWY009) over Coalbank Slough built?

It was built in 1987, making it 38 years old in 2025.

What condition is US101(HWY009) over Coalbank Slough 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 May 2023.

How much traffic does US101(HWY009) over Coalbank Slough carry?

About 31,461 vehicles per day (2022 count), of which roughly 7% are trucks.

How long is US101(HWY009) over Coalbank Slough?

The structure is 362 ft (110.3 m) long with a longest span of 70 ft (21.3 m) and a deck 87 ft wide.

Who owns US101(HWY009) over Coalbank Slough?

It is owned by the State Highway Agency.