US Bridges

U.S. Highway 101 over Outlet Crk & Ncra/Nwp RR

Fair

Mendocino County, California · 01-MEN-101-57.67 · Structure no. 10 0179

Built
1957
68 years old
Condition
Fair
inspected May 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
543 ft
7 main spans
Daily traffic
6,700
2009 count
Owner
State
State Highway Agency

About this bridge

U.S. Highway 101 over Outlet Crk & Ncra/Nwp RR is a steel stringer/multi-beam or girder carrying U.S. Highway 101 over Outlet Crk & Ncra/Nwp RR in Mendocino County, California. It was built in 1957, so it is 68 years old, older than the California average of 54.8 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 6,700 vehicles a day, roughly 20% of them trucks, projected to reach 9,662 by 2045. The structure is 543 ft (165.5 m) long and 60 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

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CarriesU.S. Highway 101
CrossesOutlet Crk & Ncra/Nwp RR
Location01-MEN-101-57.67
RouteU.S. Route 101
CountyMendocino County
StateCalifornia
Coordinates39.53608, -123.41555
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionMay 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating33.6 US tons
Inventory rating25.7 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans7 (+2 approach)
Design loadHS 20
Structure length543 ft (165.5 m)
Longest span71 ft (21.5 m)
Deck width60 ft (18.3 m)
Roadway width58 ft (17.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic6,700 (2009)
Projected traffic9,662 by 2045
Trucks20%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway
CrossesRailroad and waterway
Detour if closed123.7 mi (199 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate 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—
NavigationNo navigation control on waterway

Frequently asked questions

When was U.S. Highway 101 over Outlet Crk & Ncra/Nwp RR built?

It was built in 1957, making it 68 years old in 2025.

What condition is U.S. Highway 101 over Outlet Crk & Ncra/Nwp RR 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 U.S. Highway 101 over Outlet Crk & Ncra/Nwp RR carry?

About 6,700 vehicles per day (2009 count), of which roughly 20% are trucks.

How long is U.S. Highway 101 over Outlet Crk & Ncra/Nwp RR?

The structure is 543 ft (165.5 m) long with a longest span of 71 ft (21.5 m) and a deck 60 ft wide.

Who owns U.S. Highway 101 over Outlet Crk & Ncra/Nwp RR?

It is owned by the State Highway Agency.